Finding Interior and Exterior Angles of Triangles

This video tutorial covers the concepts of finding the measures of interior and exterior angles in triangles. It explains the theorem that the sum of the interior angles of a triangle is always 180 degrees and demonstrates how to calculate unknown angles using this theorem. The video also introduces the exterior angle theorem, which states that an exterior angle is equal to the sum of the two remote interior angles. Through various examples, the tutorial illustrates how to apply these theorems and solve for unknown variables using algebra.

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

• 90 degrees

• 360 degrees

• 180 degrees

• 270 degrees

Tags

CCSS.8.G.A.5

If two angles of a triangle are 85 degrees and 43 degrees, what is the measure of the third angle?

• 52 degrees

• 62 degrees

• 72 degrees

• 82 degrees

Tags

CCSS.8.G.A.5

In a triangle, if one angle is 111 degrees and another is 37 degrees, what is the measure of the third angle?

• 42 degrees

• 62 degrees

• 32 degrees

• 52 degrees

Tags

CCSS.8.G.A.5

If two angles in a triangle are 50 degrees and 47 degrees, what is the measure of the third angle?

• 93 degrees

• 103 degrees

• 83 degrees

• 73 degrees

Tags

CCSS.8.G.A.5

In a triangle, if one angle is 42 degrees and another is 90 degrees, what is the measure of the third angle?

• 38 degrees

• 58 degrees

• 48 degrees

• 68 degrees

Tags

CCSS.8.G.A.5

What is the measure of angle y if the angles in a triangle are 100 degrees and 48 degrees?

• 22 degrees

• 32 degrees

• 42 degrees

• 52 degrees

Tags

CCSS.8.G.A.5

What is an exterior angle of a triangle?

• An angle equal to 180 degrees

• An angle inside the triangle

• An angle formed by extending one side of the triangle

• An angle equal to 90 degrees

If an exterior angle of a triangle is 160 degrees and one of the remote interior angles is 140 degrees, what is the measure of the other remote interior angle?

• 10 degrees

• 20 degrees

• 30 degrees

• 40 degrees

Tags

CCSS.8.G.A.5

Using the exterior angle theorem, if the exterior angle is 100 degrees and one remote interior angle is 62 degrees, what is the measure of the other remote interior angle?

• 28 degrees

• 38 degrees

• 48 degrees

• 58 degrees

Tags

CCSS.8.G.A.5

If the exterior angle of a triangle is 10x + 10 degrees and the sum of the remote interior angles is 80 degrees, what is the value of x?

• 5

• 7

• 6

• 8

Tags

CCSS.8.G.A.5