Question

what error did tyler make?
72°
1
$mangle1 = 72$ by same - side exterior angles theorem
x
while there is no same - side exterior angles theorem given, same - side exterior angles are supplementary, not congruent
$mangle1=square$ (do not include the degree symbol in your answer)

Explanation:

Step1: Recall angle - relationship property

Same - side exterior angles are supplementary. That is, if two parallel lines are cut by a transversal, the sum of same - side exterior angles is 180 degrees.

Step2: Calculate the measure of ∠1

Let the given angle be 72 degrees. If we let the measure of ∠1 be \(x\), then \(x + 72=180\). Solving for \(x\), we get \(x=180 - 72\).
\(x = 108\)

Answer:

108