Illustration 8 
        The base of a parallelogram is thrice its height. If the area is 876 cm2, find the base and height of the parallelogram.
    Solution
        Let the height of the parallelogram  be x cm. 
        Then, base = 3x cm.
    ∴   Area of the parallelogram= (x × 3x) cm2 = 3x2 cm2
        But, area of the parallelogram is given as 867 cm2.
    ∴    3x2 = 867 
    ⇒     x2 = 289 
    ⇒     x2 = 172 
    ⇒     x = 17 cm.
    Thus, height = 17 cm and base = (3 × 17) cm = 51 cm.