Geometry Sides and Corners

Grade 2 · Math · Study Guide

Explore the sides and corners (vertices) of 2D shapes and learn to identify them.

Shapes are all around us! In geometry, we study the properties of shapes, including their sides and corners.

A side is a straight line that makes up part of a shape's outline. A corner (also called a vertex) is a point where two sides meet. If there are two corners, the plural word is vertices.

Different shapes have different numbers of sides and corners. A triangle has 3 sides and 3 corners. A square has 4 equal sides and 4 corners. A rectangle has 4 sides (with opposite sides equal) and 4 corners. A pentagon has 5 sides and 5 corners. A hexagon has 6 sides and 6 corners.

The number of sides always equals the number of corners in a polygon (a closed flat shape with straight sides). So if you know the sides, you know the corners!

Circles are special — they have no straight sides and no corners at all. They are curved all the way around.

When you look at shapes, count the sides by tracing around the shape. Each time you touch a corner and start going in a new direction, that is one corner. This makes it easy to count both at once!

Key terms

Side

A straight line that forms the edge of a shape

Corner (Vertex)

The point where two sides of a shape meet

Polygon

A closed flat shape made of straight sides

Triangle

A polygon with 3 sides and 3 corners

Quadrilateral

A polygon with 4 sides and 4 corners (squares, rectangles, and rhombuses are examples)

Vertices

The plural of vertex; the corners of a shape

Flashcards

Triangle

3 sides, 3 corners

Square

4 equal sides, 4 corners

Rectangle

4 sides (opposite sides equal), 4 corners

Pentagon

5 sides, 5 corners

Hexagon

6 sides, 6 corners

Circle

0 sides, 0 corners (curved)

Vertex / Corner

Where two sides of a shape meet

Side

A straight line forming the edge of a shape

Questions

1. How many sides does a pentagon have?

   1. 4
   2. 5
   3. 6
   4. 8
   Show answer

   Answer: 5

   A pentagon has 5 sides and 5 corners. 'Penta' means five in Greek.

2. A circle has 0 sides and 0 corners.

   Show answer

   Answer: True

   A circle is a curved shape with no straight sides and no corners at all.

3. A triangle has 3 sides and ___ corners.

   Show answer

   Answer: 3

   A triangle always has exactly 3 sides and 3 corners.

4. A shape has 4 sides and 4 corners with all equal sides. What shape is it?

   1. Triangle
   2. Rectangle
   3. Square
   4. Pentagon
   Show answer

   Answer: Square

   A square has 4 sides that are all the same length and 4 corners.

5. In any polygon, the number of sides is always equal to the number of corners.

   Show answer

   Answer: True

   In every polygon, the number of sides and corners (vertices) are always equal.

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