Question

What is the length of a diagonal of a 12cm by 15cm rectangle?
round to nearest tenth

Answer 1

≈ 19.2 cm

Explanation:

The diagonal of the rectangle divides the rectangle into 2 right triangles.

Using Pythagoras' identity with legs 12 and 15 and the diagonal d as hypotenuse, then

d² = 12² + 15² = 144 + 225 = 369 ( take the square root of both sides )

d =
`√(369)` ≈ 19.2 ( to the nearest tenth )