Equations with Angles Assignment

#3

Angle A and angle B are complementary angles.

The measure of angle A is 40° The measure of angle B is (5x + 10)°.

Which equation can be used to find the value of x?

• 40 = 2x + 10

• 40 + (5x + 10) = 360

• 40 + (5x + 10) = 180

• 40 + (5x + 10) = 90

Answer explanation

COMPLEMENTARY ANGLES form a RIGHT ANGLE = 90º

#4

Look at the sketch shown below.

What is the value of x?

• 165º

• 66º

• 33º

• 55º

Answer explanation

COMBINE X FAMILY AND SOLVE FOR X

#5

Look at the triangle shown below. The measures of the angles are shown in the sketch.

Part 1) Write an equation that can be used to determine the value of x.

​ (a)   ​ (b)   = ​ (c)  

• (x+10)
• 2x
• 29
• 3x
• 39
• 180
• +39

Answer explanation

COMBINE X FAMILY

X + 2X

#5

Look at the triangle shown below. The measures of the angles are shown in the sketch.

Part 2) What is the value of x?

​

• 37º

• 141º

• 56º

• 47º

Answer explanation

COMBINE X FAMILY

x + 2x BECOMES 3x

10 +29 = 39

so write the equation

3x + 39 = 180

now solve for x

#7

Angle B and angle C are supplementary angles.

The measure of angle B is 108° The measure of angle C is (4x + 2)°.

Which equation can be used to find the value of x?

• 108 + (4x + 2) = 90

• 108 + (4x + 2) = 180

• 108 + (4x + 2) = 360

• 108 = 4x + 2

Answer explanation

supplementary angles form a straight angle = 180º

#8

Look at the triangle shown below. The measures of the angles are shown in the sketch.

Part 1) Write an equation that can be used to determine the value of x.

Answer explanation

combine x family

How many x do you have?

#8

Look at the triangle shown below. The measures of the angles are shown in the sketch.

Part 2) What is the value of x?

• 45°

• 55°

• 65°

• 110°

Answer explanation

combine x family

x + x = 2x

write equation

2x + 70 = 180

Solve for x

#10

Fill in the blank to complete the statements. Not all words/numbers will be used.

​ (a)   angles have a sum of ​ 90º

​ (b)   angles have a sum of 180º.

The sum of the interior angles in a triangle have a sum of ​ ​ (c)  

• 90°

• 360°

• complementary
• supplementary
• 180º