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 and the angles opposite those sides are equal.

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, each measuring 60 degrees.

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.

Front

If two angles of a triangle are equal, what type of triangle is it?

Back

It is an isosceles triangle.

Front

In an isosceles triangle, if the vertex angle is 40 degrees, what are the measures of the base angles?

Back

The base angles each measure 70 degrees.

Front

What is the base of an isosceles triangle?

Back

The base of an isosceles triangle is the side that is not equal in length to the other two sides.

Front

How do you find the missing angle in a triangle?

Back

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

Front

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

Back

In an equilateral triangle, all sides are equal, and all angles are equal to 60 degrees.

Front

If the base of an isosceles triangle is 10 cm and the equal sides are 7 cm each, can this triangle exist?

Back

No, because the sum of the lengths of the two equal sides (7 + 7 = 14) must be greater than the length of the base (10 cm).

Front

What is the formula for the area of a triangle?

Back

The area of a triangle can be calculated using the formula: Area = 1/2 * base * height.