Question

draw PQ of length 10cm and draw its axis of symmetry.

Answer 1

take a scale & by measuring, draw a line of 10 cm. now take a rounder & measure half of length of line drawn. draw an arc by placing the rounder first on P & then on Q on both sides of line drawn.

1/2 of PQ=5 cm

Hope that it helps.

Answer 2

$10 - 5 = 5$