Step-by-step explanation:
A diameter spans from one end of (in this case, a circle) to the direct opposite end, going through the center-point. The radius, on the other hand, is half of a diameter, and spans only from the center-point to a point on the circle.
In this case:
1) Diameter = 18 km (given)
Radius = 18/2 = 9 km
2) Diameter = 1 x 2 = 2 m
Radius = 1 m (given)
3) Diameter = 17 x 2 = 34 cm
Radius = 17 cm (given)
4) Diameter = 50 mm (given)
Radius = 50/2 = 25 mm
John has a swimming pool, in which the center of the pool to the edge is 3 meters. What is the diameter? Simply multiply 3 with 2:
3 x 2 = 6 meters
6 meters is the diameter.
