a) Maria walked 420m.
This is a place for the community of learners in Room 8-16 to learn and enjoy math. It is an extension of the classroom making it accessible 24 hours a day, 7 days a week.
Thursday, November 18, 2010
Jocelle Garcia's scribe post
a) Maria walked 420m.
Jayvee's Pythagoras Scribe Post
Could these measurements form a rectangle? Justify your answer.
a²+b²=c²
22²+9²=c²
(22x22)+(9x9)=c²
484cm2+81cm 2=565
√565cm²≠ 566.44
This can't form a rectangle because a and b does not equal c.
7.What is the height of the wheelchair ramp? Give your answer to the nearest tenth of a centimetre.
a²=c²-b²
80²-79²=a²
6400-6241=159
159cm²=a²
√159cm=√a²
12.6cm²=a
The height of the wheelchair ramp is 12.6cm.
13.A cruise ship travels from Port Cassett north at a speed of 34 km/h for 2.5 h. Then it turns 90° and travels west at 30 km/h for 7.3 h. When it reaches Green Sea Island, how far is the ship from Port Cassett? Express your answer to the nearest kilometre.
a²+b²=c² 34x2.5=8.5
219²+8.5²=c² 30x7.3=219
(219x219)+(8.5x8.5)=c2
47961+72.25=48033.25
48033.25km=c²
√48033.25km=√c2
219.16km=c
The ship is 219.16km away from Port Cassett.
Wednesday, November 17, 2010
Carl's Homeworkbook Scibe Post
Nikki's Pythagoras Scribe Post
answer The are for A (6cm) is 36 cm2. B (8cm) is 64 cm2.
b) What is the area for the square attached to the hypotenuse?
The answer is, The are for the hypotenuse is 100cm
c) What is the length of the hypotenuse?
The length for the hypotenuse is 10cm2.
8)The side view of a ramp at the Grocery store is in the shape of a right triangle. Determine the length of a ramp, to the nearest centimeter.
a2+b2=c2
502+2002 =c2
(50 times 50)+(200 times 200)=c2
2500+40000=c2
42500=c2
206=c
11)The right triangle below has a square attached to the hypotenuse. What the perimeter of the triangle. Give your answer to the nearest centimeter.
The answer is 72.2
14) What are the length of b and c?Write your answer to the nearest tenth of a meter where appropriate.
The length for b is 4m. The length for c is 7.2.
Tuesday, November 16, 2010
Textbook work
6 a)-
c² - a² = b²
25² - 7² = b²
625 cm² - 49 cm² = b²
576 cm² = b²
√576 cm² = √b²
24 cm = b
6 b)-
t² - s² = r²
26² - 24² = r²
676 cm² - 576 cm² = r²
100 cm² = r²
√100 cm² = r²
10 = r
#9 -Tina wants to construct a path along the diagonal of her yard. What length will the path be? Express your answer to the nearest tenth of a metre.
a² + b² = c²
6² + 12² = c²
36 m² + 144 m² = c²
180 m² = c²
√180 m² = √c²
13.4 m = c
The length of the path will be 13.4 m long
#12-The hypotenuse of the triangle cuts the circle in half. What is the diameter of the circle? Express your answer to the nearest tenth of a centimetre.
a² + b² = c²
7² + 5² = c²
49 cm² + 25 cm² = c²
74 cm² = c²
√74 cm² = √c²
8.6 cm=c
The diameter of the circle is 8.6 cm
#15- The coordinate grid shown was drawn on centimetre grid paper. What is the length of line segment AB? Express your answer to the nearest tenth of a centimetre.
a² + b² = c²
4² +2² = c²
16 cm² +4 cm² = c²
20 cm² = c²
√20 cm² = √c²
4.5 cm = c
The line segment is 4.5 cm.
Homework!! - Pages 30 and 31 in the homework book
Using the Pythagorean Relationship
Okay,so I'm doing odds,and I think Karen is doing evens.
Pg.30-31
1.The Pythagorean relationship can be used to determine the length of the hypotenuse of a right triangle when the lengths of the two legs are known. AGREE?
3.Determine the length of the hypotenuse.Show your work.
a)
k² + j² = l²
40cm² + 9cm² = l²
(40² x 40²) + (9² x 9²) = l²
1600cm² + 81cm² = 1681cm²
√1681cm² = √l²
41cm²
b)
p² + q² = r² 12m² + 35m² = r² (12² x 12² ) + (35² + 35²) = r²
144m² + 1225m² = 1369m²
√1369m² = √r²
37cm²
5.Calculate the missing side length for each right triangle,to the nearest tenth of a centimeter.Show your work.
a)
w² + x² = y²
w² + 25² = 36²
11 = 25 - 36
√11 = 3.3
3.3²
b)
f² + g² = h²
7cm² + g² = 12cm²
49cm² + g² = 144cm²
144cm² - 49cm² = 95cm²
√95cm² = 9.7cm²
9.7cm²
7.A triangle is made up of two smaller congruent right triangles.
a)Find the Length of the hypotenuse for the right triangle,to the nearest tenth of a metre.Show your work.
4m² + 2m² = b²
(4 x 4) + (2 x 2) = b²
16m² + 4m² = b²
√20m² = 4.5m
b = 4.5m
b)Calculate the perimeter of the large triangle,to the nearest tenth of a metre.Show your work.
I don't know how to do this one..Help?
Karen's Scribe Post
a)
c² + 24² = 26²
c² + 576 =676
c² + 576 - 576 = 676 - 576
c² = 100
c = √100
c = 10m
b)
b² + a² = c²
b² + 15² = 39²
b² + 225 = 1521
b² + 225 - 225 = 1521 - 225
b² = 1296
b = √1296
b = 36cm
a)
c² = a² + b²
c² = 8² + 9²
c² = 64 + 81
c = √145
c = 12cm (nearest centimeter)
b)
c² = a² + b²
c² = 6² + 10²
c² = 36 + 100
c = √136
c = 12cm
6. Find the height of a triangle with a base of 4 cm and a hypotenuse of 11 cm. Round to the nearest tenth of a centimeter. Show your work.
a² + b² = c²
a² + 4² = 11²
a² + 16 = 121
a² + 16 -16 = 121 - 16
a² = 105
a² = √105
a = 10.2cm
8. Ellie and Lucas are going the skateboard park to try out the new ramp. Is the new ramp a right triangle? Explain your thinking.
a² + b² = c²
2² + 3² = 5²
4 + 9 = 13
13 ≠ 15 (5²)
No, it is not a right triangle because it doesn't equal the hypotenuse/5².
Lizelle's Scribe
Question 7
What is the missing length of the leg for each triangle? Give your answer to the nearest tenth of a millemetre.
My formula is:
h= i-g=h
h=9-5=4
h=4
What is the minimum distance the plaer at third base has to throw the ball to the runner out at first base? Express your answer to the nearest tenth.
a²+b²=c²
27²
Monday, November 15, 2010
Using The Phythagorean Relationship.
The following picture shows the line from 2nd to home making a right triangle.
a2+ b2= c2
(27x27) + (27x27) = c2
729m(squared) + 729m(squared) = c2
1458= c2
✔1458cm(squared)= ✔c2
38.18m= c
The following picture shows a right triangle. Find h/ c .
a2 + b2= c2
(6x6) + (10x10) = c2
36cm(squared) + 100cm(squared)= c2
136cm2= c2
✔136cm(squared) =✔c2
11.66cm= c
The following picture shows a right triangle. You are only given r & t. Find s.
a2 + b2 = c2
20(squared) + b2= 52(squared)
(20x20) + b2 = (52x52)
b2= 52(squared) - 20(squared)
b2= 2704- 400
b2= 2304 cm(squared)
✔ b2= ✔2304
b= 48cm
The following picture shows a right triangle. You are only given b and c. Find a.
a2 = c2 - b2
a2 = 9(squared) - 4(squared)
a2= 81cm2 - 16cm2
a2= 65cm
✔a2= ✔65cm
a= 8.06 cm
HOMEWORK :)
Page 103 and 104 .
Questions 1, 2, 3 and 4.
Question 1:
Jack must determine the side length of a right triangle. He decides to draw it, and then measure it, as shown. Do you agree with the method that Jack is using? Explain .
I agree with the method Jack is using, because once he knows what the two side lengths are, he can find the hypotenuse.
Question 2:
Kira calculated the missing side length of the right triangle.
Is Kira correct ? If she is correct, explain how you know. If she is incorrect, explain the correct method.
Kira is not correct, because she forgot to do this part:
194cm(squared) = y2
✔194= ✔c2
13.9= c
Tuesday, November 9, 2010
Nicholas's Scribe Post.
7.11 x 11 = 121 12 x 12 = 144
122-143
8.2 x 2 = 4 3 x 3 = 9
5-8
Filimon Scribe Post
Ishaka's square roots scribe post
a) 72
square root 64 =8 x 8
square root 72 = 8.__x 8.__
square root 81 = 9 x 9
I estimated that 8.49 was the square root of 72 calculator 8.48
b) 103
square root 100 = 10 x 10
square root 103 = 10.__ x 10.__
square root 121 = 11 x 11
I estimated that 10.15 x 10.15 was the square root of 103 calculator 10.14
c) 55
square root 49 = 7 x 7
square root 55 = 7.__ x 7.__
square root 64 = 8 x 8
I estimated that 7.42 x 7.42 was the square root of 55 calculator 7.41
6) What is an example of a whole number that has a square root between 9 and 10?
9 10
81 100
examples: 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99.
Victoria's Square Root Post
Stella is planning an outdoor wedding. She would like a square dance floor with an area of 115 m2.
a) Determine the side length of the dance floor, to the nearest tenth of a metre.
b) Stella finds out that the dance floor will be made up of floorboards that each measure 1 m2. What are the two side lengths the dance floor can have that are closest to what she wants?
c) What are the two square areas for the dance floor that Stella can choose from?
d) Which area will Stella choose? Explain.
Answers !
a.)10.7m b.) Sorry i dont know this question c.)100m2 or 121m2 d.) She will chose the 121m2 dance floor because its closer to the size she wanted.
New Question !
14. Alex is thinking of a number.
a) What number could he be thinking of?
b) Is there more than one answer? Explain
Answers!
a.) 60 b.) No, there is only one answer and the nember must be between 49 and 64. The only multiple number is 12m this is the range of 60.
Richards Scribe Post
16.a) 27m squared b) i cant find the answer . can you try finding the answer by commenting.
17.a) 324cm squared b)1296cm squared c) 36cm by 36cm squared
Kevin's Square Root Scribe Post
a) Identify a whole number with a square root between 8 and 9.
b) How many whole numbers can you find that have a square root between 8 and 9? show you work.
a) First I changed the number 8 to 64 (8x8) and 9 to 81 (9x9).
64 ? 81
64 73 81
b) There are 16 whole numbers I found.
65 = 8.0
66 = 8.12
67 = 8.18
68 = 8.24
69 = 8.30
70 = 8.36
71 = 8.42
72 = 8.48
73 = 8.54
74 = 8.60
75 = 8.66
76 = 8.71
77 = 8.77
78 = 8.83
79 = 8.88
80 = 8.94
I used perfect squares to find these.
P.s I'm not sure if I'm right so can you guys help me out? Just post your answers at the comment section and I'll take a look at them.
Nikki's Math Post
19.) Estimate 160 100. Explain how you determined your estimate.
Monday, November 8, 2010
Victoria's Pythagoras Post
Justin's Square Root Scribe Post
For each number of the following, use perfect squares to estimate the square root to one decimal place.Check your answers with a calculator
a) ✔18 b) ✔23 c) ✔35
You can estimate using perfect squares to find the square root to one decimal place like this:
✔18 is in between the perfect numbers 16 and 25. ✔16=4x4 ✔18=4.__ ✔25=5x5
✔18=4.__ because if you multiply 4.__ it equals 18.
✔23 is in between the perfect numbers 16 and 25. ✔16=4x4 ✔23=4.__ ✔25=5x5
23=4.__ because if you multiply 4.__ it equals 23.
✔35 is in between the perfect numbers 25 and 36. ✔25=5x5 ✔35=5.__ ✔36=6x6
35=5.__ because if you multiply 5.__ it equals 35.
Sunday, November 7, 2010
Paulo's Pythagoras Scribe Post
a) What is the area of each square attach to the three sides of the right triangle?
81 cm2 and 144cm2
b) Write an addition statement showing the relationship between the areas of the three squares?
81+144=225
c) Describe, using words and symbols, the relationship between side lengths of each square?
PLEASE HELP ME DESCRIBE THE RELATIONSHIP BETWEEN THE SIDE LENGTHS OF EACH SQUARE
14) Show weather each triangle in the table is a right triangle.
Triangle Side Lengths (cm)
A 9,12,15
B 7,8,11
C 7,24,25
D 16,30,34
E 10,11,14
Answer :
A is a right triangle :9 square + 12 square= 15 square
B is not a right triangle :7 square + 8 square= almost 11 square
C is a right triangle : 7 square + 24 square = 25 square
D is a right triangle : 16 square + 30 square= 34 square
E is a right triangle : 10 square + 11 square = almost 14 square
18) The diagram is made of two right triangles and five squares.
PLEASE HELP ME GET THE ANSWER
Glenn's Pythagoras Scribe Post
a) 30x30= 900mm
Cathlene's Pythagoras Scribepost
c. Write an addtion statement with the areas of the three squares
The triangle is a right angle because both the legs of the triangle is equal to the area of the hypotenuse.