Geometric constructions with compass and ruler
Plane geometry · Mathematics
Study notes
Q: Construct a 60° angle with compass and ruler only. Draw ray AB. Compass at A, arc cutting ray at C. Same radius at C, arc cutting first arc at D. Join AD: ∠DAC = 60° (△ACD equilateral - all radii equal!). Bisect it: 30°! Bisect 90°: 45°!