## Sunday, November 7, 2010

### Kim's Pythagoras Scribe Post

This post is about questions 1, 6, 13, and 20.

1. Descibe, using words and symbols, the relationship among the areas of the three squares shown.

Work
225cm²+64²= 289cm²
The sum of the areas of the two smaller squares is equal to the area of the largest square.

6. a) Write an addition statement using the areas of these three squares.

b) What is the side length of each square?
c) Describe, using words and symbols, the relationship between the side lengths of each square.

Work

a) 25cm²+144cm²= 169cm²
169cm²= 169cm²

b) √25cm²= 5cm
√144cm²= 12cm
√169cm²= 13cm

c) The sum of the areas of the two smaller squares is equal to the area of the largest square.
a² + b²= c²
5² + 12²= 13²

13. A small triangular flower bed has a square stepping stone at each of its sides. Is the flower bed in the shape of a right triangle? Explain your reasoning.

Work
4800cm²+4800cm²= 9600cm² not 9800cm²

No, the shape of the flower bed is not a right triangle because the sum of the areas of the two small squares does not equal the area of the largest square.

20. A right triangle has sides of 3cm, 4cm, and 5cm. Attached to each side is a semi-circle instead of a square. Describe the relationship between the areas of the semi-circles.

Work

╥ x r²= area of a circle
╥= 3.14

3 ÷ 2= 1.5

1.5²= 2.25

3.14 x 2.25= 7.065

4 ÷ 2= 2

2²= 4

3.14 x 4= 12.56

5 ÷ 2= 2.5

2.5²= 6.25

3.14 x 6.25= 19.625

7.065 ÷ 2= 3.5325
12.56 ÷ 2= 6.28
19.625 ÷ 2= 9.8125
3.5325 + 6.28= 9.8125
The sum of the areas of the two smaller semi-circles is equal to the area of the largest semi-circle.

1. Nice post Kim. I liked how you used pictures from the textbook for your post. I also liked the link and your video. Next time add a little more color to your post. Other than that, great job.

2. Nice post Kim. I really like the colors in your post. I also like the video. Great work.