Elementary geometry

Tetrahedron, edge, cosine, inscribed sphere, C1.

[STEP II 2010 Question 6 (Pure)]

Octahedron, polyhedron, equilateral triangle, volume, faces, vertices, ratio, C1.

[STEP I 2007 Question 5 (Pure)]

Area and perimeter of polygon, curve sketching, trigonometry, mainimisation, differentiation, C1-ish.

[STEP I 2006 Question 4 (Pure)]

Euler's formula, polyhedron, edge, vertices, faces, regular, Euclidean, C1.

[STEP III 1999 Question 4 (Pure)]

Cube, tetrahedron, polyhedra, octahedron, vertices, faces, volume, edges, C1.

[STEP III 1998 Question 6 (Pure)]

Birkhoff Maclane, C1.

[STEP II 1995 Question 5 (Pure)]

Proof by induction, plane, lines, intersection, line segments, C1.

[STEP II 1990 Question 4 (Pure)]

Proof, line segments, midpoint, intersection, C1.

[STEP I 1988 Question 4 (Pure)]