Answer:

The given figure is:

We can draw a few conclusions from this figure, which are as follows:

(i) BP = BQ

(ii) DR = DS

(iii) CR = CQ

(iv) AP = AS

Since the above drawn conclusions are tangents on the circle from points D, B, A, and C respectively.

When the LHS and RHS of the above equations are added together, we get,

DR+BP+AP+CR = DS+BQ+AS+CQ

On rearranging them we get,

(DR+CR) + (BP+AP) = (CQ+BQ) + (DS+AS)

On simplifying,

AD+BC= CD+AB