Equilateral and Isosceles Triangles Flashcard

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 equal.

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 sum of the interior angles of a triangle?

Back

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

Front

If two angles of a triangle are 30 degrees and 60 degrees, what is the measure of the third angle?

Back

The third angle measures 90 degrees, since 30 + 60 + 90 = 180.

Front

In an equilateral triangle, if one side measures 10 cm, what is the length of the other sides?

Back

The other sides also measure 10 cm, as all sides in an equilateral triangle are equal.

Front

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

Back

All angles in an equilateral triangle are equal, each measuring 60 degrees.

Front

How can you determine if a triangle is isosceles?

Back

A triangle is isosceles if at least two of its sides are of equal length.

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

If the base of an isosceles triangle is 8 cm and the height is 5 cm, what is the area?

Back

The area is 20 cm², calculated as Area = 1/2 * 8 * 5.