Question

which is the measure of ∠acd? 40° 70° 70° 100° 110° 130°

Explanation:

Step1: Recall exterior - angle property

The exterior - angle of a triangle is equal to the sum of the two non - adjacent interior angles. In \(\triangle ABC\), \(\angle ACD\) is an exterior angle, and the two non - adjacent interior angles are \(\angle A\) and \(\angle B\).

Step2: Identify the non - adjacent interior angles

We are given that \(\angle A = 40^{\circ}\) and \(\angle B=70^{\circ}\).

Step3: Calculate \(\angle ACD\)

By the exterior - angle property, \(\angle ACD=\angle A+\angle B\). So, \(\angle ACD = 40^{\circ}+70^{\circ}=110^{\circ}\).

Answer:

C. \(110^{\circ}\)