Answer
$\text{area of shaded region} = 4 - \pi \approx 0.86\text{ square units}$
Work Step by Step
Notice that the shaded region is outside the circle.
This means that the area of the shaded region is:
$\text{area of shaded region} = \text{area of the square} - \text{area of the circle}$
RECALL:
(1) The area of a square whose side length is $s$ is given by the formula $A=s^2$.
(2) The area of a circle whose radius is $r$ units is $A=\pi{r^2}$
The square has a side length of 2 units while the circle has a diameter of 2 units, which means that its radius is 1 unit.
Use the formulas above to obtain:
$\text{area of shaded region} = \text{area of the square} - \text{area of the circle}
\\\text{area of shaded region} = s^2 - \pi{r^2}
\\\text{area of shaded region} = 2^2 - \pi(1^2)
\\\text{area of shaded region} = 4 - \pi(1)
\\\text{area of shaded region} = 4 - \pi \approx 0.86\text{ square units}$
