Question

How do you do this?

Answer 1

Use the Pythagorean Theorem: a² + b² = c².

a and b are the legs of the right triangle, and c is the hypotenuse.

2) 5² + b² = 6²
    25 + b² = 36
    b² = 11
    b = 3.3 cm

3) 7² + b² = 8²
    49 + b² = 64
    b² = 15
    b = 3.9 cm

4) a² + 5² = 13²
     a² + 25 = 169
     a² = 144
     a = 12 cm