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Grade 4 (age 9-10)

Types of Quadrilaterals

Types of Quadrilaterals

A quadrilateral is a shape with four sides. You see them in notebooks, windows, and kites. Their sides, angles, and diagonals sort them into square, rectangle, rhombus, parallelogram, and trapezoid, and more conditions make a shape more special. Here you tap the buttons to explore each shape and watch how they nest inside one another.

Types of Quadrilaterals
🔷 Quadrilaterals have 4 sides
①Names depend on side length and angles
②Square, rectangle, rhombus, parallelogram, trapezoid
③Each has its own special rules
Compare Directly
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Containment of Quadrilaterals
🪆 Quadrilaterals are nested
①A square is also a rectangle and a rhombus
②Rectangles and rhombuses are parallelograms
③Parallelograms are trapezoids
④More conditions = more special!
Summary
Square
All sides equal + all angles = 90°
Most special; both a rectangle and a rhombus
Rectangle
Opposite sides equal + all angles = 90°
A quadrilateral with four right angles
Parallelogram
Opposite sides parallel + equal length
Both pairs of opposite sides are parallel
🎯 Key Points
①Square: 4 equal sides, 4 right angles
②Rectangle: 4 right angles, opposite sides equal
③Rhombus: 4 equal sides, perpendicular diagonals
④Parallelogram: opposite sides parallel
⑤Trapezoid: only one pair parallel
Examples and Unit Test
Example 1
What is a quadrilateral with four equal sides and four right angles called?
1
Tell quadrilaterals apart by side length and angle size.
2
Four equal sides and four right angles make a square.
Square
A square is the most special quadrilateral; it is both a rectangle and a rhombus.
Example 2
What is a quadrilateral with only one pair of parallel sides called?
1
Look at how many pairs of sides are parallel.
2
Only one pair of opposite sides parallel makes a trapezoid. (Two pairs = parallelogram.)
Trapezoid
One pair of parallel sides = trapezoid; two pairs = parallelogram.
Unit Test
Which quadrilateral has "four right angles and equal opposite sides"?
rhombus
rectangle
trapezoid
parallelogram
② rectangle
1
Find the quadrilateral with all four angles right.
2
Four right angles with equal opposite sides is a rectangle. (Equal sides too = square.)