Question

The flag shown above is made of overlapping

equilateral triangles ADF and BCE. Because ribbon

is to be sewn around the entire outer edge, it is

necessary to know the perimeter of the flag. If

line segment CD, line segment DE, and line

segment EF each have length 10 inches, what

is the length, in inches, of the perimeter shown

in bold?

Answer 1

`\triangle{GDE}` is equilateral

DE = GD = GE = 10 => AG = BG = 10

P = AC + AG + GB + BF + FC = 20 + 10 + 10 + 20 + 3×10 = 90