As shown in the figure below, the quadrangle PQRS is divided into four parts by the diagonal line.
The area of A is 4 cm2, B is 12 cm2, C is 15 cm2.
The area of A is 4 cm2, B is 12 cm2, C is 15 cm2.
Answer
Since the ratio of the base PO : RO is equal to the ratio of the area of the triangle A and B, it is 4 : 12 = 1 : 3.
This shows that the area ratio of the triangle D and C can be also set to 1 : 3.
Therefore, the area of D is 5 cm2 (15 × 1/3 = 5).
5 cm2
Solution
The base of the triangle A and the base of triangle B is set to PO and RO respectively. Since the ratio of the base PO : RO is equal to the ratio of the area of the triangle A and B, it is 4 : 12 = 1 : 3.
This shows that the area ratio of the triangle D and C can be also set to 1 : 3.
Therefore, the area of D is 5 cm2 (15 × 1/3 = 5).
