Two mating involute spur gears of 200 pressure angle have a gear ratio 2. The number of teeth on pinion is 20 and its speed is 250 rpm. The module pitch of the teeth is 12 mm. If the addendum on each wheel is such that the path of approach and the path of recess on each side are half the maximum possible length each, find: i) The addendum for pinion and gear wheel ii) The length of arc of contact