Question

problem 20: (first taught in lesson 24) if a = 69, find e. after you enter your answer press go. e =

Explanation:

Step1: Find the value of \( b \)

Since \( a \) and \( b \) are supplementary angles (\( a + b=180^{\circ} \)), and \( a = 69^{\circ} \), then \( b=180 - 69=111^{\circ} \).

Step2: Use the property of parallel lines

Because \( l_1\parallel l_2\parallel l_3 \), \( b = c \) (alternate - interior angles) and \( c = e \) (vertical angles). So \( e=b \).

Answer:

\( 111 \)