Isosceles and Equilateral Triangles

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length.

Tags

CCSS.4.G.A.2

Front

What is an equilateral triangle?

Back

An equilateral triangle is a triangle in which all three sides are of equal length and all three angles are equal to 60 degrees.

Tags

CCSS.4.G.A.2

Front

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

Back

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

Tags

CCSS.8.G.A.5

Front

If two angles of a triangle are equal, what can be said about the triangle?

Back

The triangle is isosceles.

Tags

CCSS.2.G.A.1

Front

In an isosceles triangle, what can be said about the angles opposite the equal sides?

Back

The angles opposite the equal sides are also equal.

Tags

CCSS.8.G.A.5

Front

How do you find the measure of an unknown angle in a triangle?

Back

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

Tags

CCSS.8.G.A.5

Front

If one angle of an equilateral triangle is 60 degrees, what are the measures of the other two angles?

Back

The other two angles are also 60 degrees.

Tags

CCSS.8.G.A.5

Front

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

Back

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

Tags

CCSS.HSG.CO.C.10

Front

Find x if the angles of a triangle are x, x, and 60 degrees.

Back

x = 60 degrees.

Tags

CCSS.8.G.A.5

Front

What is the measure of the vertex angle in an isosceles triangle if the base angles are each 40 degrees?

Back

The vertex angle is 100 degrees.

Tags

CCSS.8.G.A.5