#4 · Geometry basics · Classes 5–12
Ray
A ray starts at one point and goes on forever in one direction, like a beam of light from a torch.
Ray📐 Formula
Direction of ray OA: (cos θ, sin θ)
✏️ Worked example
A ray from O at θ = 30° points along (0.866, 0.5).
🌍 Where it is used
Sunlight, laser beams and the arms of an angle are rays.
❓ Quick check
A ray has…