shape a
shape b
shape c
shape d
the bottom triangle
A
B
C
D
Total S.A.
300
190
60
160
20
32
26
12
h=5
120
100
15
75
The bottom triangle
The area of the bottom
360
180
48
720
1003.36 ft2
370.28 ft2
742.04 ft2
1339.73 ft2