What is the area of the shaded region

Step-by-step explanation:
big circle – small circle
big
[tex]\pi \times 3.5 {}^{2} = \frac{49}{4} \pi[/tex]
small
[tex]\pi \times 1.2 {}^{2} = \frac{36}{25} \pi[/tex]
answer
[tex] \frac{49}{4} \pi - \frac{36}{25} \pi = \frac{1081}{100} \pi[/tex]