Find measures of complementary, supplementary, vertical and adjacent angles
Key Notes:
Complementary angles have measures that add to 90°.
∠ABC and ∠ CBD are complementary angles.
- Complementary angles have measures that add to 90°. When a right angle is divided into two adjacent angles, complementary angles are formed.
Learn with an example
The measure of an angle is 89°. What is the measure of its complementary angle?——–
Since the angles are complementary, their measures must add to 90°. Set up an equation and solve for n.
n+89°=90°
n+89°-89°=90°-89°
n=1°
The measure of the complementary angle is 1°.
What is the value of t?
Add the measures of the complementary angles and set the sum equal to 90°. Then solve for t.
t+57°=90°
t=90°-57°
t=33°
so ,t=33°
What is the value of r?
Add the measures of the supplementary angles and set the sum equal to 180°. Then solve for r.
r+44°=180°
r=180°-44°
t=136°
so ,t=136°
let’s practice!
