Squares and rectangles are some of the simplest shapes to make from wood, and most mitre boxes, used to quickly cut angles, are designed to make squares and rectangles. There are many reasons why one would want to make a more unusual shape, such as a pentagon. However, making a pentagon is trickier than making a simple square or rectangle. Technically, a pentagon is any polygon with five straight sides, but a regular pentagon has five sides of equal length and 108 degree angles. (see References 1 and 2)
Draw a line on your paper the length that you want each side of your pentagon to be. (see Reference 3)
Line up your protractor so that the middle of the straight edge is on an endpoint of your line. The line should run through the 0/180 mark on the protractor. (see Reference 3)
Make a mark at the 108 degree. This should make a wide angle. (see References 1-3)
Line up your ruler with the endpoint that you measured from and your mark. Measure the same length that you used for the first line; that is, if your initial pentagon side was 5 inches, measure a line that is 5 inches between the endpoint and angle mark.
Repeat steps 1-4 three times. The last side can be completed by drawing a line between the last two endpoints and enclosing the pentagon.
Cut out your pentagon template and trace onto your piece of wood. Cut each side carefully with any type of saw. Wear safety goggles when working with a saw.
You can draw a pentagon directly onto the wood, but drawing on a piece of paper makes it easier to start over should you make a mistake as well as to duplicate your pentagon if needed. To make a pentagon frame rather than a solid piece, you need five equally-sized pieces of wood with a 54 degree angle cut at the end of each piece. A power mitre saw is a good tool for this. (see Reference 4)
Always be careful when using a saw. (see Reference 4)