Angle Sum Property of a Triangle

The video tutorial explains the angle sum property of triangles, demonstrating that the sum of the interior angles of a triangle is always 180 degrees. It uses various examples and activities, such as folding triangles and using properties of parallel lines, to find unknown angles in different triangles. The tutorial also covers the use of linear pairs and exterior angle properties to solve for angles in triangles.

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

• 180 degrees

• 90 degrees

• 270 degrees

• 360 degrees

In the folding triangle activity, what do angles A, B, and C form when combined?

• An acute angle

• An obtuse angle

• A straight angle

• A right angle

If two angles in a triangle are 60 degrees and 70 degrees, what is the measure of the third angle?

• 80 degrees

• 70 degrees

• 60 degrees

• 50 degrees

In triangle ABC, if angle BAC is 83 degrees and angle ACB is 46 degrees, what is the measure of angle ABC?

• 55 degrees

• 51 degrees

• 53 degrees

• 57 degrees

What property states that the sum of the measures of a linear pair is 180 degrees?

• Corresponding angles property

• Exterior angle property

• Angle sum property

• Linear pair property

If line DE is parallel to line BC in triangle ABC, which angles are equal?

• Angles ACB and DBC

• Angles BAC and DAE

• Angles AED and ABC

• Angles ADE and DBC

In triangle PQR, if angle PRQ is 110 degrees, what is the measure of angle PRS if PRQ and PRS form a linear pair?

• 80 degrees

• 90 degrees

• 70 degrees

• 60 degrees