Finding Angle Measurements in a Triangle

This lesson teaches how to find the measure of an angle in a triangle using the other two angles. It reviews the concept that the sum of angles in a triangle is 180 degrees and explains how to combine like terms in algebraic expressions. The lesson addresses common misconceptions, such as the incorrect belief that the sum of triangle angles is 90 degrees. Through examples, it demonstrates how to calculate specific angles in a triangle using given values and expressions. The lesson concludes with a summary of the key points covered.

What is the sum of the angles in any triangle?

• 90 degrees

• 180 degrees

• 360 degrees

• 270 degrees

If one angle in a triangle is 90 degrees, what can be said about the sum of the other two angles?

• They sum up to 270 degrees

• They sum up to 180 degrees

• They sum up to 360 degrees

• They sum up to 90 degrees

In triangle abc, if angle a is 47 degrees and angle b is 65 degrees, what is the measure of angle c?

• 75 degrees

• 70 degrees

• 68 degrees

• 78 degrees

How do you solve for an angle when given expressions for the angles in a triangle?

• Multiply the expressions by 180

• Add the expressions and set equal to 180

• Add the expressions and set equal to 90

• Subtract the expressions from 180

If angle a in triangle abc is expressed as x + 11 and x is found to be 29, what is the measure of angle a?

• 40 degrees

• 60 degrees

• 29 degrees

• 50 degrees