Question

Incline mats, or triangle mats, are offered with different levels of incline to help gymnasts learn basic moves. As the name may suggest, two sides of the mat are right triangles. If the height of the mat is 7 inches shorter than the length of the mat and the hypotenuse is 1 inches longer than the length of the mat, what is the length of the mat?

Answer 1

Answer: length = 12

Explanation:

Use Pythagorean Theorem: length² + height² = hypotenuse²

length = L

height = L - 7

hypotenuse = L + 1

L² + (L - 7)² = (L + 1)²

L² + L² - 14L + 49 = L² + 2L + 1

2L² - 14L + 49 = L² + 2L + 1

L² - 14L + 49 = 2L + 1

L² - 16L + 49 = 1

L² - 16L + 48 = 0

(L - 4)(L - 12) = 0

L - 4 = 0 L - 12 = 0

L = 4 L = 12

Input L = 4 and L = 12 to find the height:

Height = L - 7 height = L - 7

= 4 - 7 = 12 - 7

= -3 = 5

↓

negative height is not valid

So, the only valid solution is L = 12