Understanding Exterior Angles in Triangles

In this video, the teacher introduces the concept of exterior angles in triangles, explaining that an exterior angle is formed when a side of a triangle is extended. The video covers a theorem stating that the sum of the two non-adjacent interior angles equals the exterior angle. Two example problems are solved: one finding the exterior angle and another finding a missing interior angle. The video concludes with a call to action to like and subscribe.

What is an exterior angle in a triangle?

• An angle that is always 90 degrees

• An angle that is equal to the sum of all interior angles

• An angle formed by extending a side of the triangle

• An angle inside the triangle

How is an exterior angle formed?

• By adding two interior angles

• By bisecting an interior angle

• By extending a side of the triangle

• By drawing a perpendicular from a vertex

According to the theorem, the exterior angle is equal to:

• The sum of the two non-adjacent interior angles

• The product of two interior angles

• The difference between two interior angles

• The sum of all interior angles

What is the sum of the two non-adjacent interior angles in a triangle?

• Equal to the exterior angle

• Equal to 180 degrees

• Equal to the adjacent interior angle

• Equal to 90 degrees

In the first example, what is the measure of the exterior angle if the two interior angles are 50 degrees and 60 degrees?

• 120 degrees

• 130 degrees

• 110 degrees

• 100 degrees

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

• 100 degrees

• 110 degrees

• 120 degrees

• 130 degrees

In the second example, if the exterior angle is 120 degrees and one interior angle is 50 degrees, what is the other interior angle?

• 80 degrees

• 70 degrees

• 60 degrees

• 90 degrees

What is the missing interior angle if the exterior angle is 120 degrees and one interior angle is 50 degrees?

• 60 degrees

• 70 degrees

• 80 degrees

• 90 degrees

How do you find the missing interior angle when given the exterior angle and one interior angle?

• Add the given interior angle to the exterior angle

• Subtract the given interior angle from the exterior angle

• Multiply the given interior angle by the exterior angle

• Divide the exterior angle by the given interior angle

What is the value of x if the exterior angle is 120 degrees and one interior angle is 50 degrees?

• 90 degrees

• 60 degrees

• 70 degrees

• 80 degrees