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

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

Back

In an isosceles triangle, the angles opposite the equal sides are equal. If you know one angle, you can find the others using the fact that the sum of angles in a triangle is 180 degrees.

Front

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

Back

In an equilateral triangle, all three angles are equal and each measures 60 degrees.

Front

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

Back

It is an isosceles triangle.

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.

Front

How do you determine if a triangle is equilateral?

Back

A triangle is equilateral if all three sides are of equal length.

Front

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

Back

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

Front

If one angle of an isosceles triangle is 36 degrees, what are the measures of the other two angles?

Back

The other two angles are each 72 degrees.

Front

In an isosceles triangle, if the equal sides are 10 cm each and the base is 8 cm, how do you find the height?

Back

You can use the Pythagorean theorem. Split the triangle in half to form two right triangles, then use the formula: height = √(10^2 - (8/2)^2).