Closed figures created with straight and curved lines are geometric shapes. Some of the geometric shapes have special names. Triangles, squares, rectangles, and circles are the most common geometric shapes.
Triangles
A triangle is a closed geometric shape formed by joining three straight lines. Triangle has three corners and three sides.
Squares
A square is a closed geometric shape formed by joining four lines of equal length. A square has four corners and four sides. All of its sides are of equal length.
Rectangles
A rectangle is a closed geometric shape formed by combining four lines. A rectangle has four corners and four sides. Opposite side lengths are equal.
Circles
You can see many circles around such as the basketball hoop, or a coin. A circle has no sides or corners. This is the most important feature that distinguishes a circle from other geometric shapes.