1) You are given the diameter of the wheel, D=55cm. When they ask how far it is around the wheel, they are asking for the **circumference** of the wheel.

The circumference of any circle is defined as: C = 2πr or πD

Where D = diameter and r = radius = D/2

a) C = πD = 55π = 172.8cm

b) Each time the tire turns a complete revolution it travels a distance equal to the circumference.

d=distance

d = C×revolutions = πDrevs = π55×50 = 8639.37 = 8639cm(rounded)

c) Similar to above;

d = C×revolutions, but this time were given the distance traveled.

250m = 55cmπ×revs, but you must convert 250m into cm first!

250m×100cm/1m= 25000cm

revs = 25000/55π = 144.68 = 155(rounded)

2) If Arthur walks around this pond on a sidewalk built around it he will cover no less than the circumference of the pond no matter where on the sidewalk he walks or how narrow it may or may not be. Arthur wants to walk **at least** 1200m

d <Crevs;

revs > d/C; revs > d/πD; revs > 1200/100π = 3.819 = 4 laps(rounded)

3) Same formula again.

d = C(revs),

d = πD(revs),

d = 30cmπ(417) = 39301.3241cm, but they wanted the answer in meters.

39301.3241cm(1m/100cm) = 393.01m = 393m(rounded)