Angle pairsAngles on a line
Name: Date:
Find the angle marked x. Give each answer in degrees.
1 degrees
2 degrees
3 degrees
4 degrees
5 degrees
6 degrees
7 degrees
8 degrees
Supplementary angles worksheets
Two supplementary angles sit along a straight line, so they add to 180 degrees. These free printable worksheets draw a pair with one marked x, cut from the mixed angle-pair page.
If they get stuck
Supplementary angles
The answer key prints on a separate page.
What's on this sheet
Split from the mixed angle-pair sheet, this page drills only the supplementary relationship, so a child fixes the fact — a straight line is 180 degrees — before the harder job of telling it apart from complementary and vertical angles.
Why this sheet works
Each figure shows two angles opening off a ruled straight line, which is the visual cue that they fill a half turn. The arithmetic is one subtraction from 180; the reading is noticing the straight line, then writing x + 115 = 180 and solving.
How this one works
One question from a sheet like this one, worked a step at a time — with a sentence saying what just happened and why.
Supplementary angles, step by step