Geometry: Complementary Equals 90 and Supplementary Equals 180 Practice
Find missing angle measures using angle relationships
Geometry: Complementary Equals 90 and Supplementary Equals 180 Practice
Find missing angle measures using angle relationships
Geometry - Grade 6-8
- 1
Angle A measures 35 degrees. Angle B is complementary to Angle A. What is the measure of Angle B?
Subtract the given angle from 90 degrees.
Angle B measures 55 degrees because complementary angles add to 90 degrees, and 90 - 35 = 55. - 2
Angle C measures 112 degrees. Angle D is supplementary to Angle C. What is the measure of Angle D?
Angle D measures 68 degrees because supplementary angles add to 180 degrees, and 180 - 112 = 68. - 3
Two angles are complementary. One angle measures 27 degrees. Find the measure of the other angle.
Complementary means the two angle measures have a sum of 90 degrees.
The other angle measures 63 degrees because 90 - 27 = 63. - 4
Two angles form a straight line. One angle measures 46 degrees. What is the measure of the other angle?
The other angle measures 134 degrees because angles that form a straight line are supplementary, and 180 - 46 = 134. - 5
Classify the pair of angles as complementary, supplementary, or neither: 40 degrees and 50 degrees.
Add the two angle measures and compare the sum to 90 and 180.
The angles are complementary because 40 + 50 = 90. - 6
Classify the pair of angles as complementary, supplementary, or neither: 73 degrees and 107 degrees.
The angles are supplementary because 73 + 107 = 180. - 7
Classify the pair of angles as complementary, supplementary, or neither: 25 degrees and 55 degrees.
Check whether the sum equals exactly 90 or exactly 180.
The angles are neither complementary nor supplementary because 25 + 55 = 80, which is not 90 or 180. - 8
In the diagram, two adjacent angles form a right angle. One angle is 38 degrees and the other angle is x degrees. Write and solve an equation to find x.
The equation is 38 + x = 90. Solving gives x = 52, so the missing angle measures 52 degrees. - 9
In the diagram, two adjacent angles form a straight angle. One angle is 125 degrees and the other angle is y degrees. Write and solve an equation to find y.
A straight angle measures 180 degrees.
The equation is 125 + y = 180. Solving gives y = 55, so the missing angle measures 55 degrees. - 10
The measure of an angle is x degrees. Its complement is 18 degrees. Write and solve an equation to find x.
The equation is x + 18 = 90. Solving gives x = 72, so the angle measures 72 degrees. - 11
The measure of an angle is n degrees. Its supplement is 141 degrees. Write and solve an equation to find n.
Supplementary angles add to 180 degrees.
The equation is n + 141 = 180. Solving gives n = 39, so the angle measures 39 degrees. - 12
A vertical ray stands on a horizontal line, making a 90 degree angle on each side of the ray. One of the 90 degree angles is split into two angles labeled 64 degrees and z degrees. Find z.
The angle z measures 26 degrees because the two angles make a right angle, and 90 - 64 = 26.