How to Graph a Perimeter Using a Calculator

Graphing calculators are handy tools. Not only do they have the functionality of a scientific calculator, but they also have the ability to graph "functions," or equations that describe a line or shape. You can use this functionality to graph the perimeter of a given shape if you know a little information about the shape you're graphing.

Things You'll Need

• Graphing calculator

Instructions

Graphing a Circle

1. Derive the equation for your circle. You must know the radius to do this. The equation is "x^2 + y^2 = r^2" where "r" is the radius of your circle.

2. Press the "y=" or equivalent button on your calculator.

3. Enter the equation for your circle and press "Graph." When you give the calculator an equation for a shape, it automatically draws the perimeter.

Graphing a Rectangle

1. Write down the equations for the left and bottom sides of your rectangle. These will be "x=0" and "y=0" respectively.

2. Derive the equations for the top and right sides of your rectangle. Use the equations "y=h" and "x=w" where "h" and "w" are the height and width of your rectangle respectively.

3. Press the "y=" button or equivalent on your calculator and enter your equations.

4. Press the "Graph" button to graph your rectangle.

Tips & Warnings

• There are infinite shapes. You'll have to get creative defining the equations for more complex shapes.

References

• Analyze Math: Equation of a Circle
• Math Open Reference: Rectangle Definition
• Math.com: Graphing Equations and Inequalities