How to Square an Octagonal Gazebo

Mark the tops of the stakes with paint. Use yellow paint on four stakes, blue paint on four stakes and red paint on eight stakes. Do not paint the last stake.

Pound the unpainted stake in the center of the space with a hammer.

Lay out an 8-foot square, using a tape measure and carpenter's square, with the unpainted stake in the center. Pound a yellow stake into each corner.

Tie a string to a yellow stake, pull it across to the opposite corner, and tie it to the opposite yellow stake. Repeat with the other pair of yellow stakes, so the strings make an "X." The two strings should cross over the top of the unpainted center stake.

Tie a string to a yellow stake and pull it around the perimeter of the square. Wrap the string around each yellow stake before moving on to the next. Tie the string to the first yellow stake, making a square.

Check each corner with a protractor to ensure that it is a perfect 90-degree angle. Adjust the stakes if necessary.

Mark the exact center of the string on each side of the yellow square.

Tie a string to the unpainted center stake. Measure exactly 4 feet out from the center stake, with the string aligned with the mark on the side of the square. Drive a blue stake into the ground at the 4-foot point. Repeat on the other three sides of the square.

Tie a string to a blue stake. Wrap the string around the perimeter of the blue stakes, making a second square. Check the corners of the blue square to ensure that each corner is at a 90-degree angle.

Drive a red stake into the ground at each point where the yellow and blue squares' strings meet. Wrap a string around the perimeter of the red stakes, one-by-one, to make an 8-foot red octagon.

Check each corner of the octagon with a protractor to ensure that it is a 135-degree angle.

Remove all stakes and string except those marking the red octagon and the center stake.