Answer:
1400 square units
Step-by-step explanation:
The area can be computed by subtracting the areas of the white rectangles at three corners from the overall 60×30 rectangle.
The upper left corner white space is 10×10 = 100 square units.
The upper right and lower left white spaces are 15×10 = 150 square units each.
Then the shaded area is ...
60×30 -100 -2(150) = 1800 -100 -300 = 1400 . . . square units
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Alternate solution
You can extend each of the horizontal edges across the figure to divide it into three rectangles. From the top down, these have dimensions and areas of ...
35×10 +60×10 +45×10 = 10(35+60+45) = 10(140) = 1400 . . . square units
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Area of a rectangle is the product of length and width.