Question

1. line de is parallel to line bc.

a. what is the measure of angle eac?
b. what is the measure of angle dab?
(from unit 1, lesson 21.)

Explanation:

Step1: Use the property of alternate - interior angles

When two parallel lines are cut by a transversal, alternate - interior angles are equal. Since \(DE\parallel BC\) and \(AC\) is a transversal, \(\angle EAC=\angle C\). So, \(\angle EAC = c^{\circ}\).

Step2: Use the property of alternate - interior angles

Since \(DE\parallel BC\) and \(AB\) is a transversal, \(\angle DAB=\angle B\). So, \(\angle DAB = b^{\circ}\).

Answer:

a. \(c^{\circ}\)
b. \(b^{\circ}\)