In a triangle, one angle is a complement of the other angle. What is the value of the third angle?
Answer:
90°
- Let us recall the fact that in a triangle, the sum of all its internal angles is 180°.
- Let us look at the definition of complementary angles: two angles are complementary if their sum is 90°.
- In the given triangle, two angles are complementary to each other. This means, the sum of two angles is 90°. Let us assume the third unknown angle is y. This means:
y + 90° = 180°
or, y = 180° - 90°
or, y = 90° - Therefore, the third angle is 90°.