Tuesday, November 16, 2010

Using the Pythagorean Relationship

Key Ideas Review.
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
40
cm² + 9cm² = l²
(
40² x 40²) + (9² x 9²) = l²
1600
cm² + 81cm² = 1681cm²
1681cm² = √l²
41cm
²

b)
p² + q² = r² 12m² + 35m² = r² (12² x 12² ) + (35² + 35²) = r²
144
+ 1225m² = 1369m²
1369 = 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
7cm
² + g² = 12cm²
49cm² + g² = 144cm²
144cm
² - 49cm² = 95cm²
95cm² = 9.7cm²
9.7cm
²

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.

4m
² + 2m² = b²
(4 x 4) + (2 x 2) = b
²
16m
² + 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?