B. 15 degrees
Since the four angles around vertex B add up to 360 degrees, and angle C is 75 degrees, we can calculate angle A by subtracting the sum of angles B and C (75 degrees) from 360 degrees:
360 - (75 + B) = 360 - 75 = 285 degrees
Now, we know that angle B is adjacent to angles A and C, meaning it forms a straight line with them. So, angle B + angle A = 180 degrees.
Substitute angle B = 15 degrees:
15 + A = 180
A = 180 - 15
A = 165
Therefore, m A = 15 degrees.
Two intersecting lines create four angles with the same vertex, labeled A, B, C, and D. Angle B is adjacent to A and C. Find m A if m C = 75 degrees.
A. 75 degrees
B. 15 degrees
C. 180 degrees
D. 105 degrees
1 answer