Equilateral and Isosceles Triangles

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 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.

Front

What are the properties of an equilateral triangle?

Back

The properties of an equilateral triangle include: all sides are equal, all angles are equal (60 degrees), and it has rotational symmetry of order 3.

Front

What are the properties of an isosceles triangle?

Back

The properties of an isosceles triangle include: two sides are equal, the angles opposite the equal sides are equal, and it has at least one line of symmetry.

Front

How do you find the height of an isosceles triangle?

Back

To find the height of an isosceles triangle, you can drop a perpendicular from the vertex angle to the base, which bisects the base and creates two right triangles.

Front

What is the formula for the area of a triangle?

Back

The formula for the area of a triangle is A = 1/2 * base * height.

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

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

Back

A triangle is isosceles if at least two of its side lengths are equal.

Front

What is the vertex angle in an isosceles triangle?

Back

The vertex angle in an isosceles triangle is the angle formed by the two equal sides.

Front

What are base angles in an isosceles triangle?

Back

Base angles in an isosceles triangle are the angles opposite the equal sides.