IB skill practice

Find dihedral angles with normals

Use normal vectors to calculate and interpret dihedral angle relationships.

Paper 1, Paper 2 5 marks Difficulty 4

Find dihedral angles with normals - visual unit-circle scan

Two plane normals have lengths 5 and 13, with absolute dot product 30. Enter \(\cos\theta\) for the dihedral angle.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.