Solutions (17−20): Length of EF = 10 − 4 = 6 m Length of GF = 8 − 4 = 4 m Area of shaded portion = Area of ABCD − Area of EFGH = (L × B) − (l × b) = (10 × 8) − (6 × 4) = 80 − 24 = 56 m2 Perimeter of EFGH = 2 (l + b) = 2 (6 + 4) = 20 m 17.