Completely forgot how to do. do i subtract or add -10 and

AC =

Step-by-step explanation:

using Pythagoras' identity on the right triangle

AC² = 10² + 6² = 100 + 36 = 136

AC =

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.