The perimeter of a semicircular protractor is $66 \mathrm{cm}$. If the radius of the protractor, correct up to two decimal places is $k \mathrm{cm}$ then find $k$ considering $\mathrm{\pi }=\frac{22}{7}$.

The difference between the circumference and diameter of a circle is $135 \mathrm{cm}$. If the radius of the circle considering $\mathrm{\pi }=\frac{22}{7}$ is $k \mathrm{cm}$, then find the value of $k$.[ write the answer in decimals]

In the figure, the chord $AB$ of a circle of radius $10 \mathrm{cm}$ subtends an angle of $90°$ at the centre $O$. If the area of the segment $ACBA$ is $k {\mathrm{cm}}^2$, then find the value of $k$. $($Take $\mathrm{\pi }=3.14)$