A chord of a circle of radius 14 cm a makes a right angle at the centre.

Let r cm be the radius of the circle and θ">θbe the angle.
We have:

$r=14 \mathrm{~cm}$ and $\theta=90^{\circ}$

Area of the sector $=\frac{\pi r^{2} \theta}{360}$

$=\left(\frac{22}{7} \times 14 \times 14 \times \frac{90}{360}\right) \mathrm{cm}^{2}$

$=154 \mathrm{~cm}^{2}$