The figure below shows an equilateral triangle, a rhombus with a 60∘ angle, and a regular hexagon, each of them containing some mutually tangent congruent disks. Let T, R, and H, respectively, denote the ratio in each case of the total area of the disks to the area of the enclosing polygon. Which of the following is true?
With calculation by splitting the figures into equilateral triangles, you can find the correct choice easily. Here we want to calculate each of H, R, and T to improve problem solving.△O1AC:O1A=2r⇒AC=r3⇒AB=2r+2r3T=4AB233πr2=4(2r(1+3))233πr2=2π(23−3)