By Christian Ornelas

Trapezoid

Trapezoid

A quadrilateral with one pair of parallel sides.

Bases

The two parallel lines are called the bases. In the picture below, AD and BC are the bases.

Legs

The two non parallel lines are called the legs. In the picture below, AB and CD are the legs.

Bases and Legs

To find the area, you need to:

1. Add both of the bases together.

2. Divide the sum by two.

3. Multiply that by the height.

The area of a trapezoid

The mid-segment (EF) is the segment that joins the midpoints of the non-parallel sides (AB and CD).

Its length is equal to the average of the lengths of the bases (AD and BC) of the trapezoid.

Mid-Segment

Isosceles Trapezoid

An isosceles trapezoid means that the base angles have the same measure.

The other pair of opposite angles also have the same measure.

The perimeter of a trapezoid is the sum of all the sides:

P = a + b + c + B

Perimeter of a Trapezoid

The angles on the same side of a leg are called adjacent angles.

NML and MLO are supplementary.

For the same reason, MNO and NOL are supplementary.

Adjacent angles

THE END