188k views
0 votes
Two angles of a triangle have measured of 55° and 65°. Which could not be a measure of an exterior angle or the triangle?

A. 115°
B. 120°
C. 125°
D. 130°

User Martha
by
7.3k points

1 Answer

7 votes

Final answer:

Only 120° could be the measure of an exterior angle of the triangle with the given interior angles. The measures of 115°, 125°, and 130° could not be exterior angles of the triangle.

Step-by-step explanation:

The question involves finding out which of the given angle measurements could not be an exterior angle of a triangle with two interior angles measuring 55° and 65°. The sum of the interior angles of a triangle is always 180°, so if we have two angles measuring 55° and 65°, the third angle must be 180° - (55° + 65°) = 180° - 120° = 60°. The exterior angle is supplementary to the interior angle of the triangle it is adjacent to, meaning they must add up to 180°. Given the interior angle is 60°, the corresponding exterior angle must be 180° - 60° = 120°. Therefore, the only possible exterior angle given in the choices is 120°, and the rest could not be measures of an exterior angle of the triangle.

User MYJ World
by
7.5k points