Height: 15x3/5=9
Trapezoidal area: (5+9)x9/2=63
The second question ∵EF is
,∴EF=(AD+BC)
Let the height of the trapezoid be h and the height of the shadow triangle be h.
Shadow of
EFxh
2= 15
(A.D.+B.C.)
The trapezoidal area is 60.
The third question:
Trapezoidal area: (7+ 19)x26/2=338.
Blank area (19-7)x26/2= 156
Shadow area: 338- 156= 182