Isosceles and equilateral triangles practice

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°.

Front

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

Back

To find the vertex angle in an isosceles triangle, subtract the sum of the base angles from 180°. If the base angles are equal, use the formula: Vertex angle = 180° - 2 * (base angle).

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°.

Front

If one base angle of an isosceles triangle measures 40°, what is the measure of the other base angle?

Back

The other base angle also measures 40° because the base angles in an isosceles triangle are equal.

Front

In an isosceles triangle, if the base angles are both 40°, what is the measure of the vertex angle?

Back

The vertex angle measures 100°.

Front

What is the relationship between the sides and angles in a triangle?

Back

In a triangle, the larger the angle, the longer the opposite side; conversely, the smaller the angle, the shorter the opposite side.

Front

How do you calculate the length of a side in an isosceles triangle using the Pythagorean theorem?

Back

For an isosceles triangle, if you know the length of the equal sides and the height, you can use the Pythagorean theorem: a² + b² = c², where 'c' is the length of the equal sides, and 'a' and 'b' are the height and half the base respectively.

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 find the length of the base in an isosceles triangle if the height is known?

Back

If the height is known, you can use the Pythagorean theorem to find the base. The base is twice the length of the base segment formed by dropping the height from the vertex to the base.