How to solve

A sign fixture consists of a $40$ kg beam pinned at point $D$ and fixed by a cable at point $A.$ The uniform beam is $1$ m long with a centre of mass at its geometric centre. A $0\mathrm{.}8$ m sign board placed on top of this beam is centred to the beam with uniformly distributed load of $125\frac{N}{m}.$ By drawing free body diagrams for the beam and sign board, determine the reaction at D $($horizontal and vertical components$)$ and the tension in cable at point $A.$

Figure $1$