Question

natasha is measuring the angles of a triangle. she measures the first two angles and gets 60° and 80°. what should be the measure of the third angle? a 10° b 20° c 40° d 220°

Explanation:

Step1: Recall angle - sum property

The sum of the interior angles of a triangle is 180°.

Step2: Let the third angle be \(x\)

We know that \(60^{\circ}+80^{\circ}+x = 180^{\circ}\).

Step3: Solve for \(x\)

\(x=180^{\circ}-(60^{\circ} + 80^{\circ})=180^{\circ}-140^{\circ}=40^{\circ}\)

Answer:

C. 40°