Final answer:
To pick up the 2-4-7 pins in bowling as a right-hander, you need to roll over the right side of the arrow on the lane.
Step-by-step explanation:
When throwing a right-hander in bowling, to pick up the 2-4-7 pins, you would have to roll over the right side of the arrow.
When a right-handed bowler releases the ball, it will initially travel toward the right side of the lane. As it rolls down the lane, it will start hooking (curving) towards the left side. The right side of the arrow corresponds to the path that the ball will travel and hit the pins at a favorable angle to knock down the 2-4-7 pins.
By rolling over the right arrow, the ball will create a diagonal trajectory across the lane, increasing the chances of hitting the pins and picking up the spare.