-_______________________________________________

Don't you just get a triangle?

Find three pieces of wood 3 cm wide and 30-50 cm long, connect them according to a right triangle (if they are not available, use a shooting gun or glue), paint them with white paint, and then mark them with a ruler. All right! ! An isosceles right triangle is easier to make. You can measure the angle with your own triangle.

I don't do compasses or abacus, and I don't think it's necessary for the seventh grade. What a waste!

PS: You can continue to add if you have any questions.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

1. First prepare three pieces of wood, 3 cm wide and 5 mm thick. The length is up to you. If you want to be bigger, you can make it longer.

2. First, use two plates with the same length as the waist, and the joint of the two plates is sawed into a 45-degree oblique angle, and then the joint becomes a 90-degree vertex angle.

3. Connect the two ends of the other board to the lower ends of the two waists, and it will be OK.