Sad Man and the animals are making words out of straws. Sad Man points out some parallel lines in them. In the warm-up session, the contestants have to make some parallel lines. Bad Man visits a sports centre, scanning for parallel lines with his line detector. Sad Man, meanwhile, has been exploring perpendicular lines. The Line Lizard makes an appearance and sings a song about eating lines. The final challenge in the Great Hall is to mark the parallel and perpendicular lines in a number of geometric shapes. The contestants do not beat the clock, so fail to win a maths card.

Viewers' Challenge

How many letters on a computer keyboard have:

• parallel lines?
• 
  
• perpendicular lines?
• 
  
• both parallel and perpendicular lines?
• 
  
• neither parallel nor perpendicular lines?

Answers

Click on a letter below to choose an answer.

	Letters with parallel lines: 8 (W, E, F, H, Z, N, M, R) Letters with perpendicular lines: 5 (E, T, F, H, L) Letters having both: 3 (E, F, H) Letters having neither: 16 (Q, Y, U, I, O, P, A, S, D, G, J, K, X, C, V, B)
	Letters with parallel lines: 7 (W, E, F, H, Z, N, M) Letters with perpendicular lines: 5 (E, T, F, H, L) Letters having both: 3 (E, F, H) Letters having neither: 17 (Q, R, Y, U, I, O, P, A, S, D, G, J, K, X, C, V, B)
	Letters with parallel lines: 7 (W, E, F, H, Z, N, M) Letters with perpendicular lines: 6 (E, T, F, H, L, X) Letters having both: 3 (E, F, H) Letters having neither: 16 (Q, R, Y, U, I, O, P, A, S, D, G, J, K, C, V, B)
	Letters with parallel lines: 7 (W, E, F, H, Z, N, M) Letters with perpendicular lines: 5 (E, T, F, H, L) Letters having both: 4 (B, E, F, H) Letters having neither: 16 (Q, R, Y, U, I, O, P, A, S, D, G, J, K, X, C, V)
	Letters with parallel lines: 7 (W, E, F, H, Z, N, M) Letters with perpendicular lines: 5 (E, T, F, H, L) Letters having both: 3 (E, F, H) Letters having neither: 15 (Q, R, Y, U, I, P, A, S, D, G, J, K, C, V, B)