The correct option is C 1512 cm2
Area of one triangular leaf
=√s(s−a)(s−b)(s−c)
s=41+28+152=842=42
Area of a triangle
=√42(42−41)(42−28)(42−15)
=√42×1×14×27
=126 cm2
Area of six triangular leaves
=126×6
=756 cm2
Since two such circles are there,
Total area to be painted red =756×2=1512 cm2