Triangle Sum, Exterior Angle and Isosceles Triangle Theorem

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Tags

CCSS.8.G.A.5

Front

What is the Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.

Tags

CCSS.8.G.A.5

Front

What is an isosceles triangle?

Back

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

Tags

CCSS.4.G.A.2

Front

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

Back

To find the missing angle, subtract the sum of the known angles from 180 degrees.

Tags

CCSS.8.G.A.5

Front

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

Back

In an isosceles triangle, the angles opposite the equal sides are equal.

Tags

CCSS.HSG.CO.C.11

Front

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

Back

It is a right triangle.

Tags

CCSS.4.G.A.2

Front

How can you determine if a triangle is isosceles using its side lengths?

Back

If two sides of a triangle are of equal length, then the triangle is isosceles.

Tags

CCSS.2.G.A.1

Front

What is the formula for finding the exterior angle of a triangle?

Back

The exterior angle is equal to the sum of the two opposite interior angles.

Tags

CCSS.8.G.A.5

Front

If the angles of a triangle are 50 degrees and 60 degrees, what is the third angle?

Back

The third angle is 70 degrees (180 - 50 - 60 = 70).

Tags

CCSS.8.G.A.5

Front

What is the significance of the base angles in an isosceles triangle?

Back

The base angles in an isosceles triangle are equal to each other.