Assuming that 12" round means a circle with a circumference of 12", its radius would be 12/(2*pi) = 6/pi inches. Its area would, therefore, be pi*(6/pi)2 = 36/pi sq inches. In terms of sq mm, that is 7393 sq mm (to 4 sig figs).
1 sq foot = 12in * 12 in = 144 sq in. 144 sq in / 12 sq inches = 12 pieces.
1 sq ft is 144 sq inches 12 sq ft is 12 times that or 1,728
1728 sq. in. 1 foot = 12 inches 1 sq. ft. = 12 in. x 12 in = 144 sq. in. 144 sq. in./ sq. ft. x 12 sq. ft. = 1728 sq.in.
Area of the circle in square inches = pi*radius squared
Area of 30 inch circle = pi*302 sq inches Area of 18 inch circle = pi*182 sq inches Difference = pi*(302 - 182) = 576*pi sq inches 1 sq foot = 1 ft*1 ft = 12 inches*12 inches = 144 sq inches so 576*pi sq inches = 576/144 *pi sq ft = 4*pi sq ft = 12.57 sq ft.
226.865/12=18.9
It is 374.12 sq inches.
8" circle = 50.26548 sq. "
Assuming that 12" round means a circle with a circumference of 12", its radius would be 12/(2*pi) = 6/pi inches. Its area would, therefore, be pi*(6/pi)2 = 36/pi sq inches. In terms of sq mm, that is 7393 sq mm (to 4 sig figs).
The radius of a circle with an area of 380 sq inches is 11 inches.
Area of a circle: pi*radius*radius
12
1 sq foot = 12in * 12 in = 144 sq in. 144 sq in / 12 sq inches = 12 pieces.
1 sq ft is 144 sq inches 12 sq ft is 12 times that or 1,728
1728 sq. in. 1 foot = 12 inches 1 sq. ft. = 12 in. x 12 in = 144 sq. in. 144 sq. in./ sq. ft. x 12 sq. ft. = 1728 sq.in.
Area of the circle in square inches = pi*radius squared