The picture shows a chest which has a uniform cross-section $ABCDE$, in which $ABCE$ is a rectangle . $M$ is the midpoint of $AB$. $CDE$ is an arc of a circle with $M$ as the centre . $AB = 32$cm , $BC = 12$cm, $BQ = 50$cm . Find the surface area of the lid , $CDETSR$, leaving answer correct to the nearest whole number .
Here's what I did before I got stuck .
I found $EM=MC = 20$ cm
I found that angle $EMC$ = $1.8545$ radian.
Then I found Arc length $EDC$ = $37.1$ cm .
Till here I got stuck... Can I get help? Thanks alot !