A farmer wishes to cultivate four different crops in equal areas in his $1 \mathrm{are}$ of land. The land he should allocate for each crop is:

The area of a circular track whose outer and inner radius is $5 \mathrm{cm} \mathrm{and} 4 \mathrm{cm}$ is:

Meenakshi is to bend a wire to form a logo of dimensions as shown in the given figure. The length of wire required is: