Riemann Sum and Definite Intergrals

Which of the following definite integrals represent the area of the shaded region? (Scaled by ones)

Which definite integral represents the area of the region enclosed by    $y=\sqrt{9-x^2}$  and the x-axis.

If  $\int_2^5\ f\left(x\right)dx=5\ and\ \ \int_4^5\ f\left(x\right)dx=\pi,\ find\ \int_5^5\ f\left(x\right)dx.$  

 $If\int_2^5\ f\left(x\right)dx=5\ and\ \ \int_4^5\ f\left(x\right)dx=\pi,\ find\ \int_5^4\ f\left(x\right)dx.$  

 $\int_2^5\ f\left(x\right)dx=5\ and\ \ \int_4^5\ f\left(x\right)dx=\pi,\ find\ \int_2^4\ f\left(x\right)dx.$  If