Could anyone tell me how to do these two?
<--- the side numbers are all 5's
If your drawing is accurate, no.
On the other hand,
if the first is a circle inside an 8x8 square, yes.
That's 64 - area of circle with radius 4 (area = pi(r^2)).
The next figure, see reply from earboth before I lead you astray.
Unfortunately it isn't clear to me which distance is labeled 5:
1. The side of a square has the length 5. Then the diameter of the circle is
Then the shaded area is calculated by:
2. The length of the radius is 5. Then the inscribed square consists of 4 isosceles right triangles. The shaded area is calculated by: