The answer is 2sqrt2

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)

x/3-10=8

x/3=18

x=48

11.2

step-by-step explanation:

when doing tangent the tangent of the angle is equal to the opposite side from the angle over the adjacent side to the angle.

tan43 = x / 12

move 12 over by multiplying each side by 12

12tan43 = x

x = about 11.2