Angle F and angle H are supplementary angles.

Question

The measure of angle F is 77°
The measure of angle H is (5x + 18)°
Which equation can be used to find the value of x?
A. 77 = 5x + 18
B. 77+ (5x + 18) = 180
C. 77+ (5x + 18 = 90
D. 77+ (5x + 18) = 360

Answer 1

Supplementary angles are two angles with a sum of 180°.

If angle F and angle H are supplementary angles then:

F + H = 180°

F = 77°

H = ( 5 x + 18 )°

so

F + H = 180°

77° + ( 5 x + 18 )° = 180°

Answer B.