Exploring the Exterior Angle Theorem

This video tutorial reviews the concept that the sum of all interior angles of a triangle is 180 degrees. It introduces the exterior angle theorem, which states that the measure of an exterior angle of a triangle is equal to the sum of the non-adjacent interior angles. The video explains what an exterior angle is, using a triangle ABC as an example, and provides a proof of the exterior angle theorem. The tutorial concludes with a call to action for viewers to subscribe to the channel.

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

• 270 degrees

• 180 degrees

• 90 degrees

• 360 degrees

Tags

CCSS.8.G.A.5

If two angles of a triangle are 50 degrees and 60 degrees, what is the measure of the third angle?

• 100 degrees

• 80 degrees

• 70 degrees

• 90 degrees

Tags

CCSS.8.G.A.5

According to the exterior angle theorem, the measure of an exterior angle of a triangle is equal to:

• The difference between the adjacent interior angles

• The sum of the non-adjacent interior angles

• The sum of the adjacent interior angles

• The sum of all interior angles

Tags

CCSS.8.G.A.5

What is an exterior angle of a triangle?

• An angle inside the triangle

• An angle formed by the intersection of two sides

• An angle formed by extending one side of the triangle

• An angle equal to 90 degrees

In triangle ABC, if angle 1 and angle 3 are non-adjacent to exterior angle X, what is the relationship between angle X and angles 1 and 3?

• Angle X is equal to angle 1 times angle 3

• Angle X is equal to angle 1 minus angle 3

• Angle X is equal to angle 1 plus angle 3

• Angle X is equal to angle 1 divided by angle 3

Tags

CCSS.8.G.A.5

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

• 360 degrees

• 270 degrees

• 180 degrees

• 90 degrees

Tags

CCSS.8.G.A.5

If angle 1 is 40 degrees and angle 3 is 50 degrees, what is the measure of the exterior angle X?

• 100 degrees

• 90 degrees

• 110 degrees

• 80 degrees

Tags

CCSS.8.G.A.5

Which of the following statements is true about the sum of angles on a straight line?

• It is always 360 degrees

• It is always 90 degrees

• It is always 180 degrees

• It is always 270 degrees

Tags

CCSS.7.G.B.5

What can be inferred if the sum of angle 2 and angle X is 180 degrees?

• Angle 2 and angle X are complementary

• Angle 2 and angle X are supplementary

• Angle 2 and angle X are equal

• Angle 2 and angle X are vertical angles

Tags

CCSS.7.G.B.5

What should you do if you learned something from the tutorial?

• Like the video

• Subscribe to the channel

• Share the video

• Comment on the video

Tags

CCSS.RI.7.7

CCSS.RI.8.7

CCSS.RI.9-10.7

CCSS.RL.6.7

CCSS.RL.8.7