Answer: < 4 = 90 degrees
Sum of a supplementary angles = 180 degrees
Vertical angles are equal
< 1 and < 2 are supplementary
<1 + < 2 = 180
< 2 and < 4 are vertical angles
Since, vertical angles are equal
Therefore, < 2 = < 4
< 1 = 90 degrees
What the measure of < 4
Since, < 2 = < 4
< 1 + < 4 = 180
< 1 = 90
90 + < 4 = 180
Isolate < 4
< 4 = 180 - 90
< 4 = 90 degrees