How to mark off a right angle, oval, and circle
To mark out a right angle, start with driving in a peg. This will be your right corner. From this, stretch a string line to mark one side of the right angle. Drive in a peg against this line exactly 3 ft. from the first peg. Attach a string 4 ft. long to the corner and another exactly 5 ft. long to the second peg. Draw them together to form a triangle. Where they touch drive in a third peg and attach a string. This line stretched between pegs 1 and 3 will be at right angles to the line between pegs 1 and 2. You can adjust your measurement to fit the size of the angle you are trying to get by using this same method. Be sure to draw out the angle and measurements on your sketch plan.
To mark a circle, drive a peg into the center. Loop over it a string exactly half the width of the circle required and draw it around at full stretch with a pointed stick inside the loop to scratch along the ground. You should have a perfect circle.
To mark an oval, use a line to mark out the full length of the oval and midway, another line at right angles to mark the width, and then drive in a peg at one end of this line. Attach to this peg a piece of string exactly half the length of the oval and draw it tight so that it touches the long line first on one side of the center and then on the other side. Drive in a peg at each of these points.
Next, measure the length from one of these pegs to the extreme end of the oval on the farther side. Make a loop of string exactly twice this length, throw it over the two pegs on the central line and pulling it taut, use a pointed stick to scratch out the oval on the ground. Again, even though this might sound confusing, if you would draw a sketch of the steps you can plainly see how you will get the perfect oval you are looking for. You will find this very helpful in measuring for a flower bed, a place for a pop up gazebo, or anything that would require an area with a specific shape.