What is the length of side d? A. 5 centimeters
B. 8 centimeters
C. 12 centimeters
D. 25 centimeters

A

Explanation:

Use formula a^2 + b^2 = c^2 but in this case letter “d” will substitute for “b”

Since 13 is hypotenuse, 13 is going to be the letter c

12 is “a” because we don’t know “d”

So it’s 12^2 + d^2 = 13^2

Simplify: 144 + d^2 = 169

Subtract to isolate d^2: d^2 = 25

Take square root from both sides to isolate d: d = 5

A