Solving for Missing Angles
Grade 9th Grade · Math · 45 min
What's Included
Learning Objective
I can solve for a missing angle or variable in complementary angle problems.
Warm-Up Video
Kayla Jones · 2:45
Complementary Angles
Guided Notes
3 key concepts
- 1
Complementary angles are two or more angles that add up to 90 degrees.
- 2
If one angle is 27° and the two angles are complementary, the other angle can be found by solving the equation 27 + B = 90, so B = 63°.
- 3
When solving for x in a complementary angle problem, set up an equation where the sum of the angles equals 90 degrees, then combine like terms and isolate x.
Practice Questions
11 questions · Short answer
Exit Ticket
Quick comprehension check
“Two angles are complementary. One angle measures 3x + 2 degrees and the other measures 28 degrees. Solve for x.”
Complete Lesson Package
Get all 3 ready-to-use resources:
Teacher Guide
Student Doc
Slides
