Understanding Angles in Isosceles Triangles

The video tutorial explains how to determine the measure of angle C in a geometric problem. It begins by identifying the properties of isosceles triangles, where the base angles are equal. The tutorial then discusses the concept of a straight angle, which sums to 180 degrees, and uses this to calculate a large angle of 146 degrees. Another isosceles triangle is introduced, and the sum of its interior angles is used to find the measure of angle C. By subtracting 146 degrees from 180 degrees, the remaining angle is 34 degrees, which is divided by 2 to find that angle C measures 17 degrees.

What is the relationship between the base angles in an isosceles triangle?

• One is double the other.

• They are equal.

• They are always different.

• They are complementary.

Tags

CCSS.7.G.B.5

What is the sum of angles in a straight line?

• 360 degrees

• 180 degrees

• 270 degrees

• 90 degrees

Tags

CCSS.7.G.B.5

If one angle in a straight line is 146 degrees, what is the measure of the other angle?

• 64 degrees

• 54 degrees

• 44 degrees

• 34 degrees

Tags

CCSS.8.G.A.5

In the second isosceles triangle, what is the measure of each base angle if the remaining angle is 34 degrees?

• 34 degrees

• 27 degrees

• 17 degrees

• 44 degrees

Tags

CCSS.8.G.A.5

What is the measure of angle C in the given problem?

• 47 degrees

• 37 degrees

• 27 degrees

• 17 degrees

Tags

CCSS.8.G.A.5