Question

Angle (<) E and <F are vertical angles. If m<E = 17x+1 and m<F =20x-14, find m<F.

Answer 1

The vertical angles theorem states that vertical angles are congruent to each other. Since angles E and F are vertical angles, this means you can make them equal to each other in an equation.

m∠E = m∠F

17x + 1 = 20x - 14

Subtract 20x from both sides.

-3x + 1 = -14

Subtract 1 from both sides.

-3x = -15

Divide both sides by -3.

x = 5

Substitute 5 for x in m∠F (20x - 14).

20(5) - 14 = 86

m∠F = 86°