1. Right-Angled Trigonometry Involving 3D Example The cuboid below has length AB = 4cm, DE = 6cm and AF = 12cm. Work out the lengths of the diagonals (i) AE(ii) BH(iii) EH A E D C B F G H

2. Example The figure is a pyramid on a square base ABCD. The edges of the base are 30cm long and the height, EH, of the pyramid is 42cm. Find a) the length of AC b) the angle EAH E C D B A H

3. Example ABCDEF is a prism with a triangular cross- section., BC = 8m, AB = 6m and CD = 20m. Find (i) AC (ii) BD (iii) the total surface area of the prism. A F E C B D