# When the Formulas Fail

On the GED® test, you may encounter shapes where the formula sheet appears to fail. Perimeter of an "ice cream cone shape"? Perimeter of an "L-shape"? Neither is on the formula sheet. In cases like this, don't panic. Remember that the perimeter can always be found by adding up all the outer sides of a shape.

## STEP 1: WATCH THE VIRTUAL CLASS VIDEO AND TAKE NOTES

### Make sure to note the following:

Remember that perimeter is defined as "the distance around a 2-dimensional shape". Whether you are finding the perimeter of known shapes, like a triangle, or unknown shapes, you can always total the lengths of all the sides in order to get perimeter.

To find the perimeter of composite shapes:

### Refer to your GED® Formula sheet and print out the example problems to follow along with the video lesson.

Do you have a question about the class video, practice, or example problems? Post a picture to our FB group for immediate assistance. Be sure to include the lesson name and level in your post.

## STEP 2: COMPLETE ONE LEVEL OF PRACTICE

Perimeter of Shapes Composed of Rectangles

## BEGINNING

Extend your knowledge of rectangles to finding the perimeter of shapes composed of rectangles.

Composite Shapes Experienced ALL

## EXPERIENCED

Find the perimeter of various compound shapes and the circumference of partial circles.

Exploring Perimeter.pdf

All my perimeter tricks in one place: estimation, math reasoning, composite shapes