Angle Pairs

Angles that always add to the same total.

10 problems · about 17 minutes · 7.G.B.5

What this lesson teaches

The child uses supplementary, complementary, vertical, and adjacent angles to find unknown angles.

From earlier lessons. Loosen up before the new work.

1 problem

Review — Telling Area from Circumference: Edging a round rug. 1 for circumference, 2 for area.
Answer 1
Why Circumference.

Straightforward practice. Get the method working first.

4 problems

Supplementary to 47?
Answer 133
Why 133 degrees.
What do vertical angles do?
Answer They are equal.
Why Vertical angles are equal.
Supplementary to 90?
Answer 90
Why 180 − 90.
Complementary to 20?
Answer 70
Why 90 − 20.

The same ideas with more to keep track of.

2 problems

Supplementary to 125?
Answer 55
Why 180 − 125.
Two lines cross and one angle is 63. What is the vertical angle?
Answer 63
Why They are equal.

Mixed problems. Work out what kind of question it is before you start.

3 problems

The Straight Line: Two supplementary angles, one is 72. What is the other?
Answer 108 degrees
Why 108 degrees.
The Right Angle: Two complementary angles, one is 35. What is the other?
Answer 55 degrees
Why 55 degrees.
The Crossing: Two lines cross. One angle is 40. What is the angle opposite it?
Answer 40 degrees
Why 40 degrees.