Question

Jika keliling segitiga 40 cm
hitung luas segitiga abc

Answer 1

K = 8 + (x+7) + (x+5)
40 = 8 + x + 7+ x + 5
40 = 8 + 7 + 5+ x + x
40 = 20 + 2x
40-20 = 2x
20 = 2x
x = 10

L = 1/2 . a . t
   = 1/2 . 8 . (x+5)
   = 1/2 . 8 . (10+5)
   = 1/2 . 8 . 15
   = 60cm