A composite figure is a two-dimensional figure made up of basic two-dimensional shapes such as one triangle and one rectangle.

When you break up a composite shape, think about it two ways:

1. Was the shape made by adding one or more simple shapes?

2. Or, could the shape be made by subtracting a smaller shape from a bigger shape?

Either way, try to imagine the fewest number of shapes.

1. In your notebook, make meaningful notes for your forgetful selves

2. CYUqs → Click the link below to open

Do your work in your notebook. Draw the composite figure. Draw the smaller, simple shapes. Include dimensions.

Check answers as you’re working. If you make a mistake, fix it. If you need help, get help. If someone else needs help, give help.

3. Stuck? Choose to persevere: review your thinking, try different approaches, ask for help, search

After completing the Check-your-understanding Questions, which were important for everyone to do?

Start by working in your notebook to figure out the length of the missing sides. After one minute, discuss your work with your seat partner. Take turns. If needed, modify or make changes to your original thinking.

1. Identify missing dimensions

1A

2. Identify missing dimension

2A

To find a missing dimension after breaking up a composite figure:

First, break it into simpler shapes and include the numbers that make sense.

Second, use addition or subtraction to determine the missing sides

Example A: To find the height of the triangle:

Example B: To find the base of the triangle:

Third, verify that you have all the dimensions