3rd Grade Rectangle Properties Worksheet: Is It a Rectangle?

What makes a rectangle a rectangle? This 3rd grade rectangle properties worksheet answers that question with a short rule box. It lists three properties. All four angles are right angles, opposite sides are equal, and there are two pairs of parallel sides. Below the box, four shapes are labelled a to d, with their side lengths in feet, metres, centimetres and inches. Next to each shape, your child answers the same three questions. Then they decide whether the shape passes all three tests. The page sits on light grid paper, so the square corners are easy to spot. Page two is the answer key, and it ends each item with a short sentence that gives the verdict.

Four answers to check

Shape a is a rectangle, because it is a square with four sides of 4 ft. Shape b is one too (7 m by 2 m), and so is shape d (3 in by 5 in). However, shape c is not a rectangle, since its bottom side slants and two of its corners are not square. All four verdicts in the key are right.

The page has a few slips. The instruction says "Identity" instead of "Identify," and "90° ?" has a stray space. In shape c, the top and bottom are both marked 5 cm, yet the key says the opposite sides are not equal. With a slanted bottom, that side would really be a little longer than 5 cm, so the label is not quite right.

At the table: a square is a rectangle too

This page counts the square as a rectangle, because it passes all three tests. That is the inclusive view, and it is the one most US classes use. Our trapezoid page uses the opposite rule, since it asks for exactly one pair of parallel sides. So a square counts as a rectangle here but not as a trapezoid there.

To test the corners, give your child the corner of a sheet of paper. They slide it into each angle of the shape. If it fits exactly, the angle is a right angle.

After the page: a rectangle hunt at home

Look for rectangles around the house, such as a door, a book cover or a phone screen. First, your child checks the corners with the paper corner. Then they measure two opposite sides with a ruler and compare the numbers. Finally, ask them to draw a shape that has two pairs of equal sides but no square corners, like a pushed-over box. It looks close to a rectangle, but it fails the first test, so it is not one.