Question

What is AB?
Answer exactly, using a radical if needed

Answer 1

AB = 7
`√(2)`

Explanation:

Using Pythagoras' identity on the right triangle.

The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is

x² = 7² + 7² = 49 + 49 = 98 ( take the square root of both sides )

x =
`√(98)` =
`√(49(2))` =
`√(49)` ×
`√(2)` = 7
`√(2)`