Topic 11Mathematics: Analysis and Approaches

C.1 3D Geometry and Triangle Solving

3D Cartesian distance and midpoint formulas (Pythagoras-twice); volume and surface area of standard solids; angles in 3D (between two lines, between a line and a plane, between two planes — all via right-triangle decomposition); sine and cosine rules including the ambiguous case; the area formula ½ ab sin C; bearings and angles of elevation/depression in navigation and surveying.

Practice questions

3D coordinate geometry — distance, midpoint, anglesSign up

3D distance and midpoint · Angles in 3D (line–line, line–plane, plane–plane)

35 min

Triangle solving — sine rule, cosine rule, applicationsSign up

Sine, cosine, and area rules — when to use which · Bearings, elevation, and depression

40 min