Try to do this on paper and follow my instructions:
Draw lines from the corner of the triangle towards the center of the circle. These will each have a length of 6'.
Now draw a line bisector from the center perpendicular to the sides of the triangle. Now you have 6 triangles of 30-60-90 degree angles.
Each 6 triangle has similar shape as half an equilateral triangle with side ratios of 1:
:2. In our case the hypotenuse is 6, so the ratio is 3:3
:6.
The area of each triangle is:
A = (3*3
)/2
So for all 6 it will be
Total area = 27

ft²= 46.77 ft²