Find Area by Composing and Decomposing Practice Test

A bulletin board is shaped like a trapezoid that you decompose into a rectangle and a triangle.

• The shorter base is $6\text{ cm}$, the longer base is $10\text{ cm}$, and the height is $4\text{ cm}$.

If you decompose it into:

• a rectangle $6\text{ cm}\times 4\text{ cm}$ and
• a right triangle with base $4\text{ cm}$ and height $4\text{ cm}$,

what is the total area?

An irregular patio can be decomposed into two rectangles that do not overlap: Rectangle 1 is $5\text{ m} \times 6\text{ m}$ and Rectangle 2 is $3\text{ m} \times 4\text{ m}$. What is the total area of the patio?