Solving for Angles with Addition

10th Grade•50 minutes

Learning Objective

I can use the angle addition postulate to solve for unknown angle measures.

The Angle Addition Postulate states if point X is interior to ∠ABC, then m∠ABX + m∠XBC = m∠ABC.

If m∠KLB = 26° and m∠BLM = 60°, and B is interior to ∠KLM, then m∠KLM = 86°.

If m∠EDC = 145° and m∠EDW = 61°, then to find m∠WDC, we can subtract 61° from 145°.

This lesson includes 9 practice questions to reinforce learning.

View questions preview

1. What does the Angle Addition Postulate state?

2. If m∠PQR = 75° and point S is in the interior of ∠PQR such that m∠PQS = 40°, what is m∠SQR?

3. In the diagram, m∠ABD = 3x + 10, m∠DBC = 5x - 2, and m∠ABC = 8x + 12. Find the value of x.

...and 6 more questions

KutaSoftware: Geometry- Angle Addition Postulate Part 1

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