Jawabanmu

2014-06-18T15:56:05+07:00
Diagonal = 40 cm
lebar      = 24 cm
panjang² = diagonal² - lebar²
             = 40² - 24²
             = 1600 - 576
panjang  = √1024 = 32 cm

keliling = 2p + 2l = 2(32) + 2(24) = 64 + 48 =112 cm
luas    = p  x l = 32 x 24 = 768 cm^2
2014-06-18T15:58:18+07:00
P = √(40² - 24²) = √(1600 - 576) = √1024 = 32 meter

kll = 2 × (32 m + 24 m)
= 2 × 56 = 112 m

Luas = 32 m × 24 m = 768 m²