L x W = SQ FT

10 ( L ) x 50 ( W ) = 500 SQ FT

L x Avg. W = SQ FT

Avg. W = ( 40 + 45 + 40 ) / 3 = 42

50 ( L ) x 42 ( Avg. W ) = 2100 SQ FT

( B x H ) / 2 = SQ FT

50 ( B ) x 25 ( H ) = 1250 / 2 = 625 SQ FT

3.14 x R x R = SQ FT

3.14 x 18 ( R ) x 18 ( R ) = 1017 SQ FT

Area A is 10 x 10 = 100 SQ FT

Area B is 15 x 20 = 300 SQ FT

Area C is 12 x b20 / 2 = 120 SQ FT

Total Area = 520 SQ FT