2-dimensional (2D) shapes have only two dimensions, length and width.

**Here are some basic regular 2D Shapes :**

A **rectangle** has **4 sides** (quadrilateral) and **4 right angles**, its opposite sides are equal, and they are parallel to each other and it has **2 lines of symmetry** and **rotational symmetry order 2**.

To calculate the **area** of a rectangle, multiply its **length by its width** (The answer will be a square measure, for example:** cm**^{2})

To calculate the **perimeter **of a rectangle, add up the length of all sides.

A **Square** has** 4 equal sides** (quadrilateral) and **4 right angles**, it has **2 pairs of parallel sides**, it has **4 lines of symmetry** and** 4 rotational symmetry.**

To calculate the **area** of a square, multiply its **length by its width ** (The answer will be a square measure, for example:** cm**^{2})

To calculate the **perimeter **of a rectangle, **add up the length of all sides** or you **can multiply the length of one side by 4 **as the length of all sides equal.

A **circle **has **no sides** and **no angles** -as you see.

All points on the edge of the circle are at the same distance from the centre.

A circle has **infinite number of line of symmetry** and **infinite order of rotational symmetry**.

The distance from the centre to the all point on the edge called **radius** (plural : radii) and the whole line from edge to another called **diameter.**

To find out the **diameter** of a circle just double the radius (radius * 2)

The perimeter of a circle called **“circumference”** which is the whole line around the circle.

To find out the **circumference** of a circle we use this formula : **C =** **π d ****π **= 22/7 ≈ 3.14 **d** = The **diameter **of the circle

A** parallelogram** has **4 sides** (quadrilateral) **4 angles,** its opposite sides are equal and they are parallel to each other, the opposite angles of a parallelogram are of equal measure, it has **2 lines of symmetry **and** rotational symmetry order 2**.

The difference between a parallelogram and a rectangle is that a rectangle has 4 right angles but a parallelogram has opposite equal angles but not right angles.

There are more than one type from triangles this one in the picture is an **Equilateral Triangle**, it has **3 equal-sides** and** 3 equal-angles**, the bottom side called **“the base” **

To find out the area of a triangle you **multiply** the** perpendicular height**, which is the line from the meddle of the base to the top angle, by** length of the base** and then** divide by 2 **.