triangles
ABC - AB=2.5, BC=1.5, CA=2 (5: 3: 4)
ADC - AC=2, CD= 1.2, DA= 1.6
BCD - BC=1.5, BD = 0.9, DB = 1.2
Area
ABC = 1/2 *AC * CB = 1/2 *2 * 1.5 = 1.5 m^2
ADC = 1/2 *AD * DC = 1/2 * 1.6 * 1.2 = 0.96 m^2
BCD = 1/2 *BD * DC = 1/2 * 0.9 * 1.2 = 0.54 m^2