Math 8: Triangles and Angle Measures
Section #1: Complementary Angles
Corresponds with 7th grade Module 6, Lesson 1 - 4
Notes # 33
Name:
Complementary Angles
Perpendicular lines are formed whenever two lines meet at a
angle, also known as a
_____________ angle.
Adjacent angles: 2 angles who have the same _____________ and share a _____________ side.
Simple terms, 2 angles that are ____________ to each other.
A
<ABC is ________________ to <ACBD
C
B
D
Complementary angles when the sum (addition) of two angles is ____________.
Example # 1 Write an equation below for each diagram.
a
34°
b
+
=
46°
+
=
Examples:
1.) Determine which angles are complementary.
State your reasoning.
b = 54°
c =36° d=26°
2.) Find the measure of x using an equation.
x
25°
a = 74°
3.) Set up an equation that models the angle relationships in the diagram. Find the measurements
of ∠𝐴𝑂𝐵 and∠𝐵𝑂𝐶.
O
A
5x°
B
(2x+20)°
C
4.) Find the measure of x and y.
32°
x°
y°
You Try:
1.) Find the measure of x using an equation.
16°
x
2.) Set up and solve an equation to find the value of 𝑥. Find the measurement of ∠𝐴𝑂𝐵 and ∠𝐵𝑂𝐶.
3.) Find the measure of x and y.
x°
y°
28°
Name:
Section #2: Complementary Angles
Corresponds with 7th grade Module 6, Lesson 1
Math 8
HW# 27
Name:
Complementary Angles
1.) One line meets two rays at a common vertex. Set up and solve an appropriate equation for 𝑥.
x°
16°
2.) Two lines meet at the common vertex of two
rays. Set up and solve an appropriate equation to
determine 𝑥.
55°
y°
x°
3.) Two lines meet at the common vertex of two rays. Set up and
solve appropriate equations to determine 𝑥 and 𝑦.
32°
x°
y°
x°
MORE ON BACK!!!!
4.) Two lines meet at the
common vertex of two rays.
y°
28°
Set up and solve an appropriate equation for 𝑥 and 𝑦.
x°
5.) The measure of a complement of an angle is 𝟑𝟐° more than three times the angle.
Find the two angles.
H.O.T Problems (Higher Order Thinking)
6.) The ratio of the measurement of an angle to its complement is 1: 2. Find the angle and its
complement.