Question

1. in △abc, m∠a = 43° and m∠b = 85°. what is m∠c?

m∠c = ______°

Explanation:

Step1: Recall triangle angle sum

The sum of angles in a triangle is \(180^\circ\), so \(m\angle A + m\angle B + m\angle C = 180^\circ\).

Step2: Substitute known angles

Substitute \(m\angle A = 43^\circ\) and \(m\angle B = 85^\circ\) into the formula: \(43^\circ + 85^\circ + m\angle C = 180^\circ\).

Step3: Calculate sum of known angles

\(43^\circ + 85^\circ = 128^\circ\).

Step4: Solve for \(m\angle C\)

Subtract \(128^\circ\) from \(180^\circ\): \(m\angle C = 180^\circ - 128^\circ = 52^\circ\).

Answer:

\(52^\circ\)