angle addition postulate
Definition of Angle Addition Postulate
- Angle Addition Postulate states that if a point S lies in the interior of ∠PQR, then ∠PQS + ∠SQR = ∠PQR.
More about Angle Addition Postulate
- If the sum of the two angles measure up to 90°, then the angles are called to be ‘complementary angles’.
- If the sum of the two angles measure up to 180°, then the angles are called to be ‘supplementary angles’.
- The angles sharing a common side are called as ‘adjacent angles’.
Example of Angle Addition Postulate
- According to angle addition postulate, m∠DAC + m∠CAB = m∠DAB. So, m∠DAB = 35° + 30° = 65°.
Solved Example on Angle Addition Postulate
Find m∠CAB. [Given ∠DAB = 64° and ∠DAC = 53°.]
Correct Answer: C
Step 1: m∠DAC + m∠CAB = m∠DAB [Angle Addition Postulate.]
Step 2: ⇒ m∠CAB = m∠DAB - m∠DAC
Step 3: ⇒ m∠CAB = 64 – 53 [Substitute.]
Step 4: m∠CAB = 11 [Add.]
Related Terms for Angle Addition Postulate
- Adjacent Angles
- Complementary Angles
- Supplementary Angles