Angles of Triangles Quick Check
4 of 54 of 5 Items
Question
Use the image to answer the question.
An illustration shows a right triangle. The right angle is at the left; the top angle is labeled a; and the angle on the right is labeled b. A line extending outward from angle a forms an exterior angle of 142 degrees.
Use the properties of exterior angles of triangles to find angle b .
(1 point)
Responses
232°
232 degrees
92°
92 degrees
52°
52 degrees
38°
To find angle b, we can use the fact that the exterior angle formed by the extension of angle a is equal to the sum of the two interior angles of the triangle that are not adjacent to angle a.
Since angle a is labeled as 142 degrees, and the right angle is 90 degrees, the sum of the two interior angles not adjacent to angle a is equal to 180 degrees - 142 degrees - 90 degrees.
180 - 142 - 90 = 70 degrees.
Therefore, angle b is 70 degrees.