Question

Anyone know how to do this question?

Answer 1

If the three circles are equal, then their diameter is 0.3, because the three diameters of the small circles together span the same space as the diameter of the large circle on the left.

So, the circuit is made by:

• Two straight sections
• Half a circumference of a circle with diameter 0.9 (right)
• Three half circumferences of circles with diameter 0.3 (left)

The circumference of a circle is given by
`C=2\pi r = \pi d` where r is the radius and d is the diameter. So, the total length is

`0.75+0.75+0.9\pi+3\cdot0.3\pi = 1.5+1.8\pi`