Hi there!

currently having trouble with a problem found on page 8 #18 in Kern and Bland Solid Mensuration

The problem states that

"Each of the four circles shown in the figure above is tangent to the other three.

(a) If the radius of each of the smaller circles is a, find the area of the largest circle.

(b) If a = 2.71 what is the area of the largest circle?"

I know that I need to form a triangle from the radii of the 3 circles but the rest is a blank to me.

I also need to show the solution that was shown in the book 1/2 (7 + 4sqrt3)a^{2}(I think? I can't see the solution clearly since its an old book)

Thank you very much

Edit: Solved it before...but I need to use that specific solution shown in the book...

MY instructor said so...