Question

an engineer wants to build a triangular - shaped building. they want one interior angle to measure 42 degrees and another angle to measure 57 degrees. what will be the measure of the last angle? select one of four 81° 73° 165° 195° remaining attempts: 1

Explanation:

Step1: Recall the sum of interior angles of a triangle

The sum of the interior angles of a triangle is \(180^{\circ}\).

Step2: Calculate the measure of the third angle

Let the third angle be \(x\). We know that \(42^{\circ}+57^{\circ}+x = 180^{\circ}\). Then \(x=180^{\circ}-(42^{\circ}+57^{\circ})\). First, calculate \(42 + 57=99\). Then \(x = 180-99=81^{\circ}\).

Answer:

\(81^{\circ}\)