The only tools you need to make these shapes are a straight ruler and a compass or dividers (Figure 1). It is also useful to have a protractor (to measure angles) and a drafting square (to make square ...

This KS2 maths article explores how an angle is a measure of a turn. Learn how to draw and measure angles using a protractor.

Packaged in this set are two metal compasses, two triangles, a six-inch ruler, a four-inch protractor, a pencil for the compass, a pencil sharpener, an eraser, and a lead refill.

Using a protractor, measure an angle of 40⁰ on the right-hand endpoint of the 9 cm line (to match the original triangle), mark it with a cross and draw a line.

Yaluke has created a Raspberry Pi Pico-powered protractor that can be used to calculate rotation data for simulating steering wheels when driving.

But you don’t have to break out the protractor; you can easily use a level to determine the angle of the cut.