Answer:
1. 3-4-5 method
2. Rope method
3. Optical square method
Step-by-step explanation:
1. A measuring tape, two ranging poles, pegs and three person's are needed.
First person holds together btw thumbs and finger the zero mark, the second person holds between thumb and finger the 3m mark on the tape and the third person holds the 8m, when all sides of the rope are stretched, a triangle is formed and angle near one is a right angle.
2. One loop of the rope is placed around peg A with a peg through other loop make a circle on the ground place peg B & C where circle crosses the base line and peg D is place half way between peg B & C, allowing peg D & A to form lines perpendicular to base line thereby forming a right angle.
3 this are simple instruments used to set out right angles and they are single and double prismatic square.