Much appreciated!
find the area of each shaded region. assume that all angles that appear to be right angles are right angles.

Step-by-step explanation:

we know that

The area of the shaded region is equal to the area of complete rectangle minus the area of the smaller inside rectangle

so

Alternative Method

The area of the shaded region is equal to the area of three rectangles

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

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