Exploring the Interior Angle Triangle Sum Theorem

This video tutorial covers the Triangle Sum Theorem, explaining how the sum of interior angles in a triangle equals 180 degrees. The instructor demonstrates solving triangle problems of varying difficulty levels, from easy to hard, using step-by-step methods. The tutorial also includes finding missing angles in triangles, reinforcing the application of the theorem.

What is the main focus of the next two lessons in Unit 3?

• Learning about polygons

• Learning about different kinds of angle relationships

• Learning about quadrilaterals

• Learning about circles

What is the sum of the interior angles of a triangle?

• 360 degrees

• 90 degrees

• 180 degrees

• 270 degrees

Tags

CCSS.8.G.A.5

If angle A is 50 degrees and angle B is 60 degrees, what is the measure of angle C in a triangle?

• 70 degrees

• 80 degrees

• 90 degrees

• 100 degrees

Tags

CCSS.8.G.A.5

In the easy level problem, if angle B is 85 degrees and angle C is 50 degrees, what is the value of angle A?

• 60 degrees

• 50 degrees

• 55 degrees

• 45 degrees

Tags

CCSS.8.G.A.5

In the medium level problem, if angle A is 5x + 4, angle B is 48 degrees, and angle C is 83 degrees, what is the value of x?

• 10

• 7

• 8

• 9

Tags

CCSS.8.G.A.5

In the hard level problem, if angle A is 6x + 10, angle B is x + 2, and angle C is x, what is the value of x?

• 19

• 22

• 20

• 21

Tags

CCSS.8.G.A.5

What is the measure of angle A if x = 10 and angle A is 5x + 5?

• 65 degrees

• 50 degrees

• 55 degrees

• 60 degrees

Tags

CCSS.7.G.B.5

What is the measure of angle B in a right triangle?

• 90 degrees

• 75 degrees

• 60 degrees

• 45 degrees

Tags

CCSS.8.G.A.5

If angle C is 3x + 5 and x = 10, what is the measure of angle C?

• 40 degrees

• 35 degrees

• 45 degrees

• 30 degrees

Tags

CCSS.7.G.B.5

What should be the sum of all interior angles in a triangle?

• 90 degrees

• 120 degrees

• 150 degrees

• 180 degrees

Tags

CCSS.8.G.A.5