The maximum area of a triangle inscribed in a semicircle having radius $10 \, cm$ is $\ldots \ldots \ldots \, cm^2$.

It is proposed to build a single circular park equal in area to the sum of areas of two circular parks of diameters $16 \, m$ and $12 \, m$ in a locality. The radius of the new park would be (in $m$)

If the area of a circle is $154 \, cm^2$,then its perimeter (circumference) is (in $cm$):

In a circle with radius $21 \, cm$,the length of a minor arc is $33 \, cm$. Find the measure of the angle subtended at the centre by this arc. Also,find the area of the minor sector and the area of the minor segment formed by it.

$A$ wire fence is to be put up all around a circular ground with diameter $105 \, m$. The length of the fence is $\ldots \ldots \ldots \ldots \, m$.

$\widehat{ACB}$ is a minor arc of $\odot(O, 8 \, cm)$. If $m\angle AOB = 45^\circ$, the length of minor $\widehat{ACB}$ is $\dots \, cm$. (in $\pi$)