An arch is in the form of a semi-ellipse. It is 8 m wide and 2 m high at the centre. Find the height of the arch at a point 1.5 m from one end.

Question

$\begin {array} {1 1} (A)\;1.56 \: m & \quad (B)\;3.12 \: m \\ (C)\;0.78 \: m & \quad (D)\;2.43 \: m \end {array}$