**Perimeter and Area**

**Perimeter and Area**

**Perimeter and Area**

For each shape, you can find the perimeter and area.

**Perimeter **is just the **distance around the outside of the shape **and the **area **is the **amount of space the shape takes up. **

Different shapes have different ays to find the perimeter and area. This chart shows the formulas for a few basic shapes.

Letâ€™s look at each shape and learn more about its area and perimeter.

**Circles**

**Circles**

Symbols

**Ď€ (pi)**is just a special number almost equal to 3.14 and used for a circleâ€™s area and perimeter**r**is the**radius**of the circle as shown in the picture**d**is the**diameter**of the circle and is**double the radius**

Area

The area of a circle is found by

**squaring the radius**(multiplying radius x radius) and**multiplying that by Ď€**

Perimeter

The perimeter of a circle can be found by

**multiplying 2**times the**radius**times**Ď€**This is also the same as multiplying the

**diameter times Ď€**

**Parallelogram**

**Parallelogram**

Symbols

**b**is the**base**, or bottom of the parallelogram**h**is the**height**or the distance from the top straight to the bottom (straight line)**s**is the**slanted sides**of the shape

Area

The area is found by

**multiplying**the**base**and**height**

Perimeter

The

**perimeter**is just**adding all four sides**of the shape, or**two**times the**base**plus**two**times the**sides**

**Rectangle**

**Rectangle**

Symbols

**l**is the**length**(**long**side)**w**is the**width**(**short**side)

Area

The area is found by

**multiplying**the**length**and**width**

Perimeter

The perimeter is just

**adding**all**four sides**of the shape, or**two**times the**width**plus**two**times the**length**

**Rhombus**

**Rhombus**

Symbols

**d**_{1}**d**_{2}**diagonals**of a rhombus**s**is the**side**of a rhombus (**same**for all**four equal sides**)

Area

The area is

**multiplying**the**diagonals**and**dividing**the result by**2**

Perimeter

The perimeter is

**adding**all**four sides**, or**4 times s**

**Square**

**Square**

Symbols

**s**is the**side**of a square (**same**for all**four e****qual****sides**are**equal**)

Area

The area is

**squaring**the**side**length (**side x side**)

Perimeter

The perimeter is

**adding**all**four sides**, or**4 times s**

**Trapezoid**

**Trapezoid**

Symbols

**b**_{1}**b**_{2}**bases**of a trapezoid**h**is the**height**of the trapezoid**s**_{1}**s**_{2}**two sides**of a trapezoid

Area

The area is

**adding**the**bases**together,**dividing**that result by**two**, and**multiplying**it by the**height**

Perimeter

The perimeter is found by

**adding**all**four sides**together (**bases**plus**two**other**sides**)

**Triangle**

**Triangle**

Symbols

**b**represents the**base**of a triangle**h**represents the**height**of a triangle**s**represents all the**side**lengths

Area

The area is found by

**multiplying**the**base**and**height**and**dividing**that result by**2**

Perimeter

The perimeter is all the

**sides added**together

**Example 1. **Find the area and perimeter of the triangle on the right:

**Example 1.**Find the area and perimeter of the triangle on the right:

**Area**: the area of a rectangle is the length times width. The **length **in this example is **7** and the **width **is **4**. So the area would be:

4 x 7 = **28 in.**

**Perimeter**: the perimeter is **adding **all of the **sides **together, or **length plus width times 2. **So the perimeter would be:

(4 + 7) x 2 = 11 x 2 = **22 in.**

**Example 2. **Find the area and perimeter of the triangle on the right:

**Example 2.**Find the area and perimeter of the triangle on the right:

The area of this triangle is the height times base divided by 2. The **height **is **7** and the **base **is **24**. So the area would be:

(7 x 24) / 2 = 168 / 2 = **84 in.**

The perimeter of this triangle is all the **sides added together.** So the perimeter would be:

7 + 24 + 25 = **56 in.**

Memorizing these formulas is important because they are the basic formulas that you can see in many problems. Here are some links you can use to get more practice or learn the formulas again.