Proving Quadrilaterals Are Parallelograms

Front

What is a parallelogram?

Back

A parallelogram is a quadrilateral with opposite sides that are both equal in length and parallel.

Front

What are the properties of a parallelogram?

Back

1. Opposite sides are equal in length. 2. Opposite angles are equal. 3. The diagonals bisect each other.

Front

How can you prove that a quadrilateral is a parallelogram using sides?

Back

If both pairs of opposite sides are equal in length, then the quadrilateral is a parallelogram.

Front

How can you prove that a quadrilateral is a parallelogram using angles?

Back

If one pair of opposite angles are equal, then the quadrilateral is a parallelogram.

Front

What is the relationship between the diagonals of a parallelogram?

Back

The diagonals of a parallelogram bisect each other.

Front

If two sides of a quadrilateral are parallel and equal in length, what can be concluded?

Back

The quadrilateral is a parallelogram.

Front

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

Back

The sum of the interior angles of a quadrilateral is 360 degrees.

Front

If the opposite sides of a quadrilateral are parallel, what can be concluded?

Back

The quadrilateral is a parallelogram.

Front

In a parallelogram, if one angle measures 70 degrees, what are the measures of the other angles?

Back

The opposite angle is also 70 degrees, and the adjacent angles are 110 degrees each.

Front

What is the formula for the area of a parallelogram?

Back

Area = base × height.