Florida Grade 3 Math · Geometric Reasoning
What this Grade 3 benchmark means, worked examples, common mistakes, and a free printable worksheet.
Created by a Florida mom · Published by Tropical Learning LLC
A composite figure is made of rectangles that don't overlap, like an L-shaped pool or room. Students find its area by splitting it into rectangles and adding their areas.
To find the perimeter, add the lengths of all the outside sides. The line where the rectangles meet is inside the figure, so it is not part of the perimeter. Each rectangle is no bigger than 12 units by 12 units.
Official benchmarkSolve mathematical and real-world problems involving the perimeter and area of composite figures composed of non-overlapping rectangles with whole-number side lengths.
On the FAST test: part of the Grade 3 reporting category Geometric Reasoning, Measurement, and Data Analysis and Probability, which is about 23–29% of the test.
Worked Example 1
Worked Example 2
Perimeter only counts the outside edges. The shared side is inside the figure.
The L-shape is not a full rectangle. Split it into rectangles and add: 30 + 16 = 46 square feet.
Draw the shape on grid paper and color each rectangle a different color. Find each area, then add.
Help your child build math confidence with original interactive questions aligned with Florida's B.E.S.T. Mathematics Standards.
Start Practicing FreeIndependent Educational Platform. FastChomp is published by Tropical Learning LLC and is not affiliated with, sponsored by, or endorsed by the Florida Department of Education. FAST and Star assessment names are referenced for informational purposes only. FastChomp practice questions are original educational materials, not official Florida FAST assessment questions.