Geometry: Classifying Polygons
Identify and sort polygons by sides, angles, and properties
Geometry: Classifying Polygons
Identify and sort polygons by sides, angles, and properties
Math - Grade 4-5
- 1
A shape has 3 straight sides and 3 vertices. What type of polygon is it?
Count the sides first.
The shape is a triangle because it has 3 straight sides and 3 vertices. - 2
Look at the shape shown. Is it a polygon? Explain why or why not.
The shape is not a polygon because it has a curved side. Polygons must be closed shapes made only of straight line segments. - 3
A polygon has 5 sides. What is the name of this polygon?
Think of the prefix penta, which means five.
A polygon with 5 sides is called a pentagon. - 4
Classify the polygon shown by the number of sides.
The polygon is a hexagon because it has 6 sides. - 5
A shape has 4 sides, 4 vertices, and all angles are right angles. Its opposite sides are equal. What is the most specific name for this shape?
A square also fits some of these facts, but this description only says opposite sides are equal.
The shape is a rectangle because it has 4 right angles and opposite sides that are equal. - 6
Look at the quadrilateral shown. Classify it as a square, rectangle, rhombus, trapezoid, or parallelogram. Choose the most specific name.
The quadrilateral is a trapezoid because it has exactly one pair of parallel sides. - 7
A polygon has 8 sides and 8 vertices. What is the name of this polygon?
The prefix octa means eight.
A polygon with 8 sides and 8 vertices is called an octagon. - 8
A triangle has 3 equal sides. Classify the triangle by its sides.
Equal sides help you name the triangle.
The triangle is an equilateral triangle because all 3 sides are equal in length. - 9
Look at the triangle shown. Classify it by its angles.
The triangle is a right triangle because it has one right angle. - 10
A polygon is closed and has 7 straight sides. What is the name of the polygon, and how many vertices does it have?
For polygons, the number of sides matches the number of vertices.
The polygon is a heptagon, and it has 7 vertices because polygons have the same number of sides and vertices. - 11
Is the shape shown a regular polygon or an irregular polygon? Explain your answer.
The shape is an irregular polygon because its sides and angles are not all equal. - 12
A quadrilateral has two pairs of parallel sides, but its angles are not right angles. What type of quadrilateral could it be?
Opposite sides stay the same distance apart in this type of quadrilateral.
The quadrilateral could be a parallelogram because it has two pairs of parallel sides and does not need to have right angles. - 13
Classify the shape shown using the most specific name: triangle, quadrilateral, pentagon, hexagon, or octagon.
The shape is a pentagon because it has 5 sides. - 14
A square is also a rectangle. Explain why this statement is true.
Focus on the angle rule for rectangles.
A square is also a rectangle because it has 4 sides and 4 right angles. A rectangle does not have to have two long sides and two short sides, so a square fits the definition. - 15
Sort these polygons by number of sides: triangle, octagon, quadrilateral, pentagon, hexagon. Write them from fewest sides to most sides.
Use the side counts 3, 4, 5, 6, and 8.
The polygons in order from fewest sides to most sides are triangle, quadrilateral, pentagon, hexagon, and octagon.