Question

Find the value of x. Then find the measure of each labeled angle.

Answer 1

x = 19.5

4x + 12 = 90 degrees

Explanation:

We know it is a right angle, meaning 90 degrees.

4x + 12 = 90

4x = 78

x = 19.5

Answer 2

• x = 19.5
• 4x+12 = 90

Explanation:

You want to know the measure of the angle marked (4x+12)° at the transversal crossing parallel lines at right angles.

Right angle

The □ symbol on the diagram indicates the lines cross at right angles. The measure of a right angle is 90°. This means all of the angles where the transversal crosses the parallel lines have measures of 90°, including the one marked (4x+12)°.

We can solve for x using this relationship:

4x +12 = 90 . . . . . . . . . answer to the second part

x +3 = 22.5 . . . . . . . divide by 4

x = 19.5 . . . . . . . . subtract 3 . . . answer to the first part