Question

The figure shows the design of a rectangular windowpane. The four horizontal lines are parallel. The measure of angle 6 is 53 degrees. What is the measure of angle 12? Write and solve an equation to find the answer.

Answer 1

∠6 and ∠12 are supplementary angles. That means, they add up to 180°

`\angle6+\angle12=180\degree`

Substitute ∠6 by 53° to find ∠12.

`53+\angle12=180`

Subtract 53 from both sides to find ∠12.

`\begin{gathered} 53+\angle12-53=180-53 \\ \angle12=127\degree \end{gathered}`

Answer: ∠12 = 127°.