The cratering charge is primarily used to interfere with the mobility of track vehicles. If you were to line the charges at a 90 degree angle, most track vehicles can do a back and forth push to get through, as long as they have some momentum. With 45 degrees, it forces track vehicles to approach the obstruction with much less momentum if they are going to meet the craters head on.
Remember, in most cases, a cratering charge line will not completely stop enemy mobility, but it will slow them down. The 45 degree angle simply forces the enemy to do more work in pushing through the craters since they have to use less momentum each push.
Use a protractor or bisect a 45 degree angle with a compass and a straight edge
draw a base and use this to draw an equilateral triangle each angle of an equilateral triangle adds up to 60 degrees. To have an angle of 120 degree use this angle and then draw another side of a triangle next to it to get a 120 degree angle.
You can use a protractor.
A protractor.
Use a protractor to draw a 55 degree angle and indicate that the angle needs to be measured once around the circle and then some.
use a protractor
Use a protractor.
Use a protractor
Use a protractor.
it is used as an degree. It is an unit of angle.
Easiest is to use a protractor. Alternative: Draw a 90 degree angle. Bisect the external angle so that it is 45 degrees. Trisect that angle so that the angle adjacent to the 90 degree angle is 15 deg Then 90 + 15 degrees = 105 degrees. Both, bisection and trisection require the use of a compass (and ruler).
Unless you are ready for some complicated trigonometry, I would suggest that you use a protractor and draw a 50 degree angle BEYOND a right angle.