Q86 of 131 Page 226

Altitudes MN and MO of parallelogram MGHK are 8 cm and 4 cm long respectively (Fig. 9.40). One side GH is 6 cm long. Find the perimeter of MGHK.

We know that, Area of a parallelogram = b × h (corresponding height)


Area of MGHK with GH as base = Area of MGHK with HK as base


GH × MN = HK × MO


6 × 8 = HK × 4


∴ HK = 12 cm


Since opposite sides of a parallelogram are equal to each other,


MK = GH = 6 cm


GM = HK = 8 cm


∴ Perimeter of parallelogram MGHK = GM + MK + KH + HG = 8 + 6 + 8 + 6 = 36 cm


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