Question

In the figure below, lines j and k are parallel, lines m and n are parallel and 2 angles are shown. What is the measure of x

O 20
O 30
O 40
O 60
80

Answer 1

The measure of the angle x is 80°. The correct option is the fifth option;

• 80°

The steps used tom find the angle x are as follows;

The sum of the 30° angle and the adjacent angle are corresponding angles to the 110° angle

Let y represent the adjacent angle

30 + y = 110

y = 110 - 30

y = 80

The angle adjacent to the 110° angle is a linear pair with the 110°, therefore, the angle is 180 - 110 = 70

Let z represent one of the angles adjacent to the angle x

The angle z is therefore;

180 - (70 + 80) = 30

z = 30

The sum of the angle z and the angle x is an alternate interior angle to the 110° angle, therefore;

z + x = 110

30 + x = 110

x = 110 - 30

x = 80