## Wednesday, November 17, 2010

### Raelynn's Homework Book Post: pg. 33 Numbers 4,6,7

Pythagorean Relationship.
Homework Book pg. 33
Numbers 4, 6, 7.

4.) The foot of a ladder is 1m from a wall. If the ladder is 6cm long, how far up the wall does the ladder reach? Give the answer to the nearest tenth of a metre. Show your work.

a² - b² = c²
6² - 1² = c²
(6x6) - (1x1) = c²
36cm² - 1cm² = 35 cm²
35cm² = c²
√35cm² = √c²
5.9cm² = c² (round up will be 6)

It will be 5.9/6 far up the wall.

6.) The width of a rectangle is 8cm, and its diagonal is 17cm.

a) Calculate the length of the rectangle. Show your work.
c² - b² = a²
17² - 8² = a²
(17x17) - (8x8) = a²
289cm² - 64cm² = 225cm²
225cm² = c²
√225cm² = √c²
15cm² = c²

b) Calculate the area of the rectangle.
120cm²

7.) A quadrilateral has a width of 17cm and a length of 26cm. A diagonal is 31cm. Is the quadrilateral a rectangle? Justify your answer.

a² + b² = c²
26² + 17² = c²
(26x26) + (17x17) = c²
676cm² + 289cm² = 965cm²
965cm² = c²
√965cm² = √c²
31.06cm²

Answer: No, the corners do not meet at right angles because 17² + 26² ≠ 31²

Enjoy this video. Hope it helps.

2. The link is where it says "Pythagorean Relationship". (:

3. Great job Raelynn, I liked that you have the answers for your questions. Although you didn't have letter B number 6, overall great job.

4. Great scribe, Raelynn! The pictures are well done, and I liked how you had answers for each question. It was colorful as well. Good job!

5. Great job Raelynn! I loved the pictures in your post, and I liked the colours you used to identify the key words in the text. Your post was very well done and it was very understandable. Again, good job!

6. Great post Raelynn. I really like your pictures. I just noticed the small mistake you make in question 4. the ladder is 6 meters not 6 centimeters and you kept on saying centimeters. Other than that i liked that you showed all your work and gave simple sentence answers. Keep it up Raelynn.

7. Great job Raelynn. It looks very neat and i liked how you used the colors well. Great job.

8. Good job, Raelynn. I liked the video you posted and all the colours were nice. Good job.

9. Great Post Raelynn, its very neat BUT next time add a link ok? :)

10. Good post, very informative.