Instruction: Construct an angle of 30° with the given side.
Goal: 3L 3E
Available tools:
- Move
- Point
- Line
- Circle
- Perpendicular Bisector
- Angle Bisector
- Intersect
Pack: Beta
Previous level: 2.2
Next level: 2.4
3L 3E solution[]
Let A be the initial point of the given ray.
- Construct a circle C1 with an arbitrary center B on the ray and radius AB, intersecting the ray on C
- Construct the circle C2 with center C and radius BC, intersecting circle C1 on D and E
- Construct line AD
2V solution[]
- Construct line AE
Explanation[]
You want the angle of 30° to be the inscribed angle of circle B that will subtends the same arc as a central angle of 60°, which you can get by constructing an equilateral triangle. By constructing circle C, you get BCD, an equilateral triangle, so the arc CD is the arc you want.
