Keliling bangun 30 cm, luas bangun adalah.... A. 24 cm B. 30 cm C. 48 cm D. 60 cm

Keliling = 30cm
= 1x + 9 + 1x + 10 + 2x - 1
= 4x + 18 = 30
= 4x = 30-18
= 4x = 12
X = 12/4 = 3

x + 9 = 3 + 9 = 12
2x - 1 = 6 - 1 = 5

12 x 5 / 2 = 30 cm2 (B)