Grade 7 · Math
Complete a straight angle practice
Use the 180-degree sum of adjacent angles on a straight line.
Opening your practice adventure…
Try a sample
Two angles form a straight angle of 180°. One measures 80°. How many degrees is the other?
- 80
- 100
- 110
- 90
See the answer & why
100
Angles on a straight line total 180°. 180 − 80 = 100°.
A little hint: Subtract the known angle from 180 degrees.
A teaching tip
Confirm the diagram or description says the angles form a straight line.