Parallelogram

Parallelograms are an important thing to review for the ACT, because they tend to be something students are less familiar or comfortable with. Problems involving parallelograms can therefore become an easy place for students to lose points. Some key things to remember about parallelograms are as follows.

Adjacent Angles

• Adjacent angles in a parallelogram are supplementary, meaning that they add up to 180

Area Formula

The area of a parallelogram has the same formula as a rectangle: A = bh, but because it’s vertical sides are not perpendicular to the base, the height is not equal to the length of the side of the shape.

• The area of a parallelogram is equal to the shape’s base multiplied by the height of a vertical line drawn from the shape’s top left corner down to the base

This is similar to finding the height of a non-right triangle, where the height has to be created by dropping a vertex down to the base.