what is the length of a diagonal of a rectangular picture whose sides are 3 inches by 4 inches

Answer 1

a^2 + b^2 = c^2

3^2 + 4^2 = c^2

9 + 16 = c^2

5 = c

Answer 2

3 4 5 right triangle
3^2 + 4^2 = 25 = 5^2