Use the properties of exterior angles of triangles to find angle b .
bottom right is 90 degress
bottom left is b
top is 142 degress
(1 point)
232°
52°
38°
92°
The sum of the exterior angles of a triangle is always 360 degrees.
In this case, we know that the top angle is 142 degrees and the bottom right angle is 90 degrees.
Therefore, the sum of the two known angles is 142 + 90 = 232 degrees.
Since the sum of the exterior angles of the triangle is 360 degrees, we can find angle b by subtracting the sum of the two known angles from 360 degrees:
360 - 232 = 128 degrees
Therefore, angle b is 128 degrees.