please answer experts fast

please answer experts fast (28) There is a mark on the outermost part of a wheel of radius 30 centimetres. Now the mark is close to the ground as shown in the figure. If the wheel rolls 31.4 centimetres on a straight line, then a) Find the angle by which the wheel rotates (use It = 3.14 as an approximation). b) What will be the height of the mark from the ground?