Take note that the problem has the statement "the distance around the lens" since lens are usually circular, then the question is finding the PERIMETER of the lens.
- the lens is a circle (we will use 3.1416 as the pi)
- the diameter of the lens is 102 cm
- the distance around the lens or the perimeter of the lens
Perimeter of circle = dπ = 102 cm (3.1416)
102 cm (3.1416)
= 320 . 44 cm (rounded to 2 decimal places
Answer: The distance around the lens is 320.44 cm rounded to 2 decimal places.