The diagonal of a quadrilateral is 20 cm in length and the lengths of perpendiculars on it from the opposite vertices are 8.5 cm and 11.5 cm. The area of the quadrilateral is
Given : A quadrilateral
Diagonal AC = 20 cm
Perpendiculars to diagonal AC are: BL = 11.5 cm and DM = 8.5 cm
Now,
Area (quad. ABCD) = area (ABC) + area (
ADC)
Area of triangle = × (base) × (height).
Therefore
Area of quad ABCD = × (AC) × (BL) +
× (AC) × (DM)
= × (20) × (11.5) +
× (20) × (8.5) = 115 + 85 = 200 cm2
Therefore area of the quadrilateral ABCD is 200 cm2.