Question

Jason was given a triangle that had a side length of 10m and a hypotenuse of

15m. When he substituted these values into the Pythagorean Theorem, he got 102 + 152 = c2

.

Part A. Find Jason’s mistake and explain it.


Part B. Solve for the missing length, show your mathematical thinking, and justify your answer.

Answer 1

The pythagorean theorem is:

H =
`√(s_1^2 + s_2^2)`

With H being the hypotenuse, s1 one side, s2 the other one. He already has a side and the hypotenuse so he has to calculate the inverse formula:

s2 =
`√(H^2 - s_1^2)`

So the real side will be:

square root of (15^2 - 10^2) = square root of (225 - 100) = 125 m

Jason made a mistake calculating the squares of the hypotenuse and the side, he didn't subtract and didn't take the root of the result.