Question

If the diameter of a wheel is 0.5 meters, then the radius of the wheel is how many centimeters

Answer 1

25 centimeters
The diameter of the circle is 0.5 meters which equals to 50 centimeter
Radius is half of a diameter so half of 50 centimeter is 25 centimeter

Answer 2

Radius = diameter x 0.5
0.5x0.5 = 0.25meter

0.25 meter x 100 cm (100cm in one meter) = 25cm

also for future reference circumference = pie x r squared.