Answer:
Step-by-step explanation:
The triangle is isosceles. That means that the unmarked side is also x
The Pythagorean Theorem applies
x^2 + x^2 = 4^2
2x^2 = 16 Divide by 2
2x^2/2 = 16/2
x^2 = 8
x^2 = 2 * 2 * 2
sqrt(x^2) = sqrt(2 * 2 * 2)
The rule is take one of a pair of factors out of the root sign and through the other member of the pair away. The third 2 stays under the root sign.
x = 2sqrt(2)
