# Perimeter & Area Calculators

## Knowledge

### What is the perimeter and area?

When you enter the fourth grade, you will begin to learn perimeter and area. Perimeter and area are the basic knowledge of primary school mathematics that students first come into contact with, which lays the foundation for later learning of higher-level knowledge such as geometry.

#### •What is the perimeter?

The perimeter refers to the sum of the lengths of the sides of a shape, that is, the length of the outer frame of the shape. For example, how many meters does it take to run around a playground? That is, what is the perimeter of the playground.

#### •What is the area?

The area refers to the size of the surface surrounded by each side, which is the inner part of the outer frame. For example, if you want to know how many square meters of turf are needed to cover the playground, you need to know the area of the playground.

#### •What's the difference between area and perimeter?

Perimeter and area are completely different. First, they have different meanings. As mentioned above, perimeter is the distance around a shape, and area is the amount of space taken up by a two-dimensional shape. Secondly, their calculation methods are different. Finally, perimeter and area are measured in different units. Generally, the longer the perimeter of a figure, the larger the area.

### How to find the perimeter and area?

To calculate perimeter and area, first we need to know what their units of measurement are. Area is measured in square units (m^{2}, cm^{2}, etc.). Perimeter is measured in units (m, cm, feet, etc.). Next, let's learn how to calculate the perimeter and area of the following six common shapes.

#### •How to find the perimeter and area of a square?

A Square is a shape with all four sides equal and all angles equal to 90 degrees.

P = 4a

A = a^{2}

#### •How to find the perimeter and area of a rectangle?

A rectangle is a shape with opposite sides equal and all angles equal to 90 degrees.

P = 2a+2b

A = ab

#### •How to find the perimeter and area of a triangle?

A triangle is a shape with three straight sides and three angles.

P = a+b+c

A = *1**2*bh

#### •How to find the perimeter and area of a parallelogram?

A parallelogram is a simple quadrilateral with two pairs of parallel sides.

P = 2a+2b

A = bh

#### •How to find the perimeter and area of a trapezoid?

A trapezoid is a quadrilateral with no sides parallel.

P = a+b+c+d

A = *1**2*h(a+b)

#### •How to find the perimeter and area of a circle?

In case of a circle, the distance of the outer line of the circle is called the circumference. And the area of a circle is the region occupied by it in a plane.

C = 2πr

A = πr^{2}