Understanding Area ( Parallelograms and Triangles)

Front

Understanding Area

Back

Area is the number of square units that cover a two-dimensional region without gaps or overlaps.

Front

Principle of Matching Figures

Back

If two figures can be placed one on top of the other so they match exactly, they have the same area.

Front

Properties of a Parallelogram: Sides

Back

Opposite sides have the same length.

Front

Height of a Parallelogram

Back

The height is the perpendicular distance from the base to the opposite side.

Front

Parallel Sides in Parallelograms

Back

Parallelograms have opposite sides that are parallel.

Front

Area formula for a triangle.

Back

Front

Definition of a polygon.

Back

A polygon is a closed, two-dimensional shape with straight sides that do not cross each other.

Front

Method 2 for finding area.

Back

Decompose and Rearrange: Cut the shape and rearrange the pieces into a familiar shape whose area you can easily find.

Front

Method 3 for finding area.

Back

Subtract Missing Pieces: Consider the shape as a familiar figure with missing parts, find the area of the complete figure, and subtract the areas of the missing pieces.

Front

Practice problem: Parallelogram area.

Back

A parallelogram has a base of 8 units and a height of 5 units. Its area is 40 square units.