Let A(0,0),B(7,2),C(5,9),D(12,11)∴ Area of △ABC=21​​075​029​111​​=21​⋅1(63−10)=253​ sq unit ∴ Area of △ACD=21​​0512​0911​111​​=21​⋅1(55−108)=253​ sq unit ∴ Area of parallelogram ABCD= Area of △ABC+ Area of △ACD=253​+253​=53 sq unit