What you need to know

The labelled 942.48 mm is the curved length of a semicircle. A semicircular arc is half a full circumference, so its arc length is pi x r. The diameter is twice the radius.

Tip 1

Use the curved arc length, not the 600 mm dimension shown elsewhere on the sculpture.

Tip 2

Divide the semicircular arc length by pi to find the radius, then double it.

How to solve it

For a semicircle, arc length = pi x r.

r = 942.48 / pi = 300 mm.

Diameter = 2 x r = 2 x 300 mm.