Dari gambar di samping jika keliling ABC=70CM tentukan

Keliling = 70

3x – 4 + x – 3 + 4x + 5 = 70

8x – 2 = 70

8x = 70 + 2

8x = 72

x = 72 : 8 = 9

a. nilai x = 9 cm

b. AB = 4x + 5 = 4.9 + 5 = 36 + 5 = 41 cm

c. BC = x – 3 = 9 – 3 = 6 cm

d. AC = 3x – 4 = 3.9 – 4 = 27 – 4 = 23 cm