A circumference of 47.12 feet.
Area = 15*25 = 375 square feet
100
Area = 15*30 = 450 square feet
Area = 15 times 8 = 120 square feet.
A circumference of 47.12 feet.
75ft
Area = 15*25 = 375 square feet
15ft
100
Is the 30ft the radius or the diameter. The area of a circle = Pi x (radius squared), so, if the diameter is 30ft, making the radius 15ft, the area would be Pi x(15 squared) square feet, and the area of its semicircle would be half of that, so the area required = Pi x (15 squared) divided by 2 = 353.429 sq ft On the other hand, if the diameter is 15ft, making the radius 7.5ft then the area required = Pi x (7.5 squared) sq ft for the full circle and half as much for the semicircle = 88.3573 sq ft As an extra; you will find that the area of the smaller semicircle is exactly one quarter of that of the larger semicircle, and I wonder if you can reason out why that is so.
Area = 15*30 = 450 square feet
Area = 15 times 8 = 120 square feet.
12ft x 15ft = 180ft2
Its height is: 8 feet
15ft is 5 yds, so 15ft x 15ft is the same as 5yds x 5yds which would equal 25 square yards.
140