Question

what would you need before you could say, m<1 + m<2 = 180°?*
o angle 1 and angle 2 are supplementary angles.
o angle 1 and angle 2 are complementary angles.
o angle 1 and angle 2 are congruent.
o angle 1 and angle 2 are in an isosceles triangle.

Explanation:

Step1: Recall the definition of supplementary angles

Supplementary angles are two angles whose sum is \(180^{\circ}\).

Step2: Analyze each option

• If angle 1 and angle 2 are in an isosceles triangle, their sum is not necessarily \(180^{\circ}\).
• If angle 1 and angle 2 are congruent, their sum is not necessarily \(180^{\circ}\).
• If angle 1 and angle 2 are complementary, their sum is \(90^{\circ}\), not \(180^{\circ}\).
• If angle 1 and angle 2 are supplementary angles, by definition, \(m\angle1 + m\angle2=180^{\circ}\).

Answer:

angle 1 and angle 2 are supplementary angles.