Lay a piece of paper on a table or flat surface. Choose any type of paper you would like, including lined paper, plain paper or cardstock.
Place a ruler on the paper. To make a rectangle, begin by drawing a horizontal line on the piece of paper using the ruler and a pencil. Choose a length for the rectangle while you are drawing the line. The length of the rectangle can be any measurement you desire. For example, draw the length to 5 inches.
Lay the ruler vertically. Start at the edge of the line you drew. Draw a line vertically up from the end of the line as far as you would like. When drawing rectangles, the length and width can vary. The length and width can be equal, forming a square which is a type of rectangle. For example, draw your line 3 inches long. This is the width of the rectangle. Make sure that the line is straight, forming a 90-degree angle with the first line.
Draw the other two lines. Use your ruler to complete the rectangle by drawing the other horizontal line and the other vertical line. The other horizontal line must also be 5 inches; while the other vertical line must be 3 inches. Make sure that your lines are straight in order to form 90-degree angles on all four corners.
Cut out the rectangle with a pair of scissors. You now have a paper rectangle. You can do anything you desire with this paper cutout.