Triangles with a Missing Angle

Front

What is the sum of the angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

If one angle of a triangle is 90 degrees, what type of triangle is it?

Back

It is a right triangle.

Front

How do you find the missing angle in a triangle if two angles are known?

Back

Subtract the sum of the known angles from 180 degrees.

Front

What is the measure of angle \(\gamma\) if angles \(\alpha = 60\degree\) and \(\beta = 40\degree\)?

Back

\(\gamma = 180\degree - (60\degree + 40\degree) = 80\degree\)

Front

What is the measure of angle \(\gamma\) if angles \(\alpha = 70\degree\) and \(\beta = 70\degree\)?

Back

\(\gamma = 180\degree - (70\degree + 70\degree) = 40\degree\)

Front

What is an isosceles triangle?

Back

An isosceles triangle has at least two sides of equal length and the angles opposite those sides are equal.

Front

What is an equilateral triangle?

Back

An equilateral triangle has all three sides of equal length and all three angles measuring 60 degrees.

Front

If \(\gamma = 100\degree\), what are the possible measures for angles \(\alpha\) and \(\beta\)?

Back

\(\alpha + \beta = 80\degree\); they can be any pair of angles that add up to 80 degrees.

Front

What is the relationship between the angles in a triangle?

Back

The angles in a triangle are supplementary, meaning they add up to 180 degrees.

Front

What is the measure of angle \(\gamma\) if angles \(\alpha = 50\degree\) and \(\beta = 70\degree\)?

Back

\(\gamma = 180\degree - (50\degree + 70\degree) = 60\degree\)