**Introduction to** **geometry plane shapes**:

In mathematics, the plane shapes are the shapes which are given in the topic geometry. In geometry, the plane shapes are made by the combination of different lines. In geometry, there are different kinds of plane shapes. The plane shapes are given as circle, triangle, square, and rectangle. In this topic we are going to see about the types of plane shapes with formulas. The types of plane shapes with formulas are given below.

The names of types of plane shapes are given as,

**Square**

**Rectangle**

**Triangle**

**circle**

The area and perimeter are the two formulas used by plane shapes on the basis of the sides.

The plane shapes with diagrams and formulas are given below:

**Square:**

The formulas for square is given as,

**Area = a ^{2}**

**Perimeter = 4a**

**Rectangle:**

The formulas for Rectangle is given as,

**Area = l*w = length x width**

**Perimeter = 2(l +w)**

**Triangle:**

** **

**Circle:**

**Area = `pi`****r ^{2}**

**Perimeter = 2****`pi`****r**

Some of the examples based on the plane shapes are given below.

Example 1: Find the area of the square given that a = 20?

**Solution:**

Area formulas for square is given as,

Area = a^{2}

Area = 20^{2}

Area = 400

The area of square is calculated as 400

**Example 2:** Find the perimeter of the rectangle given that l = 12, b = 15?

**Solution:**

Perimeter formulas for Rectangle is given as,

Perimeter = 2(l +w)

Perimeter = 2(12 + 15)

Perimeter = 2*27

**Perimeter = 54**

The perimeter of rectangle is calculated as 54

**Problem 1**: Find the area for this triangle given that b = 9, h = 12?

**Answer is given below:**

The area of triangle is calculated as 54

**Problem 2**: Find the perimeter of the circle given that r = 10?

**Answer is given below:**

The perimeter of rectangle is calculated as 62.8