(i) PQB and PBC have same height PQ.
Ratio of areas of triangles with equal heights are proportional to their corresponding bases.
A(PQB )/A(PBC) = BQ/BC
(ii) PBC and ABC have same base BC.
Ratio of areas of triangles with equal bases are proportional to their corresponding heights.
A(PBC) / A( ABC) = PQ/AD
(iii) ABC) and ADC have equal heights AD.
Ratio of areas of triangles with equal heights are proportional to their corresponding bases.
A( ABC) /A( ADC) = BC/DC
(iv) Ratio of areas of two triangles is equal to the ratio of the products of their bases and corresponding heights.
A( ADC) /A( PQC) = DC×AD/QC×PQ