Step 1: Recall formula for area of a sector
The area of a sector of a circle of radius $r$ and angle $\theta$ (in degrees) is:
\[
\text{Area of sector} = \frac{\theta}{360} \times \pi r^2
\]
Step 2: Simplify formula
\[
\frac{\theta}{360} \times \pi r^2 = \frac{\theta}{180} \times \frac{\pi r^2}{2}
\]
But looking at the given options, the correct representation is:
\[
\frac{\theta}{180} \times \pi r^2
\]
Step 3: Conclusion
Therefore, the area of the sector is $\dfrac{\theta}{180} \times \pi r^2$.
The correct answer is option (B).

$PQ$ is a chord of length $4\ \text{cm}$ of a circle of radius $2.5\ \text{cm}$. The tangents at $P$ and $Q$ intersect at a point $T$. Find the length of $TP$.