Use facts about supplementary angles to solve the following problem. Two angles are supplementary and have measures m∠ABC=15° and m∠CBD=x°. What is the value of m∠CBD ?
180°
75°
15°
165°
The sum of two supplementary angles is always equal to 180°.
Given that m∠ABC = 15°, and m∠ABC and m∠CBD are supplementary angles, we can calculate the value of m∠CBD as follows:
m∠ABC + m∠CBD = 180°
15° + x° = 180°
Subtracting 15° from both sides:
x° = 180° - 15°
x° = 165°
Therefore, the value of m∠CBD is 165°.