Missing Side (Area) E
- Use the area of a rectangle to figure out a missing side length.
- Divide the area by the known side to find the unknown side.
- Check that the side lengths you found make the correct area when multiplied.
finding length of a side Worksheets
Free area & perimeter worksheets with answer key. No login or account needed. From finding the area or perimeter visually to using math we've got you covered. A grading column and quick grade scale maker grading a breeze and a modified pages help with lower level learners or when just introducing a topic. Great for teachers or for homeschool.
About these worksheets
Students practice finding a missing side length of a rectangle or right triangle when given the area or perimeter. These worksheets reinforce the relationship between side lengths, area, and perimeter through reverse calculation — dividing area by a known side or subtracting known sides from a total perimeter. Problem sets span third grade through middle school, with some including decimal values.
Missing Side (Perimeter) E
- Use the perimeter of a rectangle to figure out one missing side length.
- Add the known side lengths and subtract from the total perimeter to find what is left.
- Use the fact that opposite sides of a rectangle are equal to solve for the unknown side.
- Write the answer with the correct measurement units.
