From the corner

Area

= (3 / 4 x 4^{2} + 1 / 4 x 2^{2} + 1 / 4 x 1^{2}) π

= 1 / 4 (48 + 4 + 1) π

1 = / 4 (53) π

1 = 31 / 4 π

Middle of longest

Area

= (1 / 2 x 4^{2} + 2 x 1 / 4 x 2 . 5^{2} + 2 x 1 / 4 x 0 . 5^{2}) π

= 111 / 4 π

Middle of shortest

Area

= (1 / 2 x 4^{2} + 2 x 1 / 4 x 3^{2}) π

= 121 / 2 π