Question 745312
{{{drawing(300,300,-33,33,-15,51,
circle(0,0,10),circle(-20,0,10),circle(20,0,10),
circle(-10,17.321,10),circle(10,17.321,10),circle(0,34.641,10),
red(triangle(-20,0,20,0,0,34.641)),green(line(0,0,0,34.641)),
green(rectangle(0,0,2,2))
)}}} The red triangle is an equilateral triangle with side length 40cm (4 circle radii). Its height is the length of the altitude drawn in green:
{{{(10cm)*sin(60^o)=(10cm)*(sqrt(3)/2)=about34.64cm}}} (rounded)
To get the height of the whole stack, we have to add one circle radius below that altitude, and one circle radius above the altitude for a total length of
{{{10cm+34.64cm+10cm=highlight(54.64cm)}}}