What you need to know

The true length follows the curved centreline rather than measuring straight across. The wave is symmetrical. Each half contains a 1,000 mm radius arc and a 1,500 mm radius arc. Both arcs turn through 30 degrees. Arc length is R x theta, with theta measured in radians.

Tip 1

Calculate one half of the wave first, then double it.

Tip 2

Convert 30 degrees to radians: 30 x pi / 180 = pi / 6. Remember the 250 mm straight section at each end.

How to solve it

Outer arc: 1,000 x pi / 6 = 523.60 mm.

Inner arc: 1,500 x pi / 6 = 785.40 mm.

One curved half = 523.60 + 785.40 = 1,309.00 mm.

Both curved halves = 2 x 1,309.00 = 2,618.00 mm.

Add the two 250 mm straight ends: 2,618.00 + 500 = 3,118.00 mm.