Properties of Parallelograms

Front

What are the properties of a parallelogram?

Back

1. Opposite sides are equal in length. 2. Opposite angles are equal. 3. Consecutive angles are supplementary. 4. The diagonals bisect each other.

Front

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

Back

360 degrees.

Front

If one angle of a parallelogram is 95°, what are the measures of the other angles?

Back

The opposite angle is also 95°, and the consecutive angles are 85° each.

Front

What does it mean for angles to be congruent?

Back

Congruent angles have the same measure.

Front

What does it mean for angles to be supplementary?

Back

Supplementary angles add up to 180 degrees.

Front

If ABCD is a parallelogram, what can be said about the lengths of sides AB and CD?

Back

AB is equal to CD.

Front

If the diagonals of a parallelogram bisect each other, what does this imply?

Back

It implies that the two triangles formed by the diagonals are congruent.

Front

How do you find the length of a diagonal in a parallelogram?

Back

Use the law of cosines or the Pythagorean theorem, depending on the information given.

Front

What is the relationship between the opposite sides of a parallelogram?

Back

Opposite sides are equal in length.

Front

If one angle of a parallelogram is 70°, what is the measure of the adjacent angle?

Back

The adjacent angle is 110° (70° + 110° = 180°).