In triangle ABC ,AB=20 cm BC =21 cm. If perimeter of triangle ABC is 70 cm, find its area. Share with your friends Share 2 Manbar Singh answered this In ∆ABC, we have,AB = 20 cm; BC = 21 cm and AC = ?Perimeter of ∆ABC = 70 cmNow, AB + BC + CA = 70⇒20 + 21 + CA = 70⇒CA = 29 cmSo, we have, a = 20 cm; b = 21 cm; c = 29 cmNow, semiperimeter, s = 702 = 35 cmNow, area of ∆ABC = ss-as-bs-c=3535 - 2035 - 2135 - 29=35 × 15 × 14 × 6=210 cm2 1 View Full Answer Sony ⚛⚛⚛⚛ answered this Given:we have ?ABC, AB=20, BC=21 Peri.=70 AB+BC+CA=Perimeter 20+21+CA=70 CA=70-41=29 semi peri.=70/2=35 by using Heron's formula area= 210.sq.cm If this answer of mine satisfies ur query then please thumbs up 1 Vinesh answered this double of perimeter 0
