Given is the shape of a triangle with base = 7 feet and height = 4 feet.
We know the formula for area of triangle is given as follows :-
[tex] Area\; of\; Triangle=\frac{1}{2} *(Base)*(Height) \\\\
Area = \frac{1}{2} (7)(4) \\\\
Area = \frac{28}{2} \\\\
Area = 14 \;squared \;feet [/tex]
So, the area of a blade is 14 squared feet.
There are four blades on wind mill. Then area of all four blades would be 4 times 14.
Hence, total area of all four blades = 4 x 14 = 56 squared feet.
