Choose the answer that is closest to the area of the shaded region?

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus

a 90 degree rotation across the the origin followed by a reflection across the x-axis.

step-by-step explanation: