Question

What is the length of EF in the right triangle below?

Answer 1

Answer:

A

Step-by-step explanation:

Since the triangle is right use Pythagoras' identity to find EF

The square on the hypotenuse is equal to the sum of the squares on the other two sides, that is

EF² + DF² = DE² ← substitute values

EF² + 12² = 18², that is

EF² + 144 = 324 ( subtract 144 from both sides )

EF² = 180 ( take the square root of both sides )

EF = $\sqrt{180}$ → A