Diketahui pankang persegi dengan panjang 8 lebihnya dari lebarnya.jika keliling persegi panjang 40cm,maka luasnya adalah... tolong beserta uraiannya
dindadin1
Kliling = 2 ( 8+ l + l ) 40 = 2 ( 8 + 2l ) 40 = 16 + 4l 40 -16 = 4l 24/4 = l 6 = l panjang = 8 + l = 8 + 6 = 14 cm luas = p x l = 14 x 6 = 84 cm²
40 = 2 ( 8 + 2l )
40 = 16 + 4l
40 -16 = 4l
24/4 = l
6 = l
panjang = 8 + l
= 8 + 6
= 14 cm
luas = p x l
= 14 x 6
= 84 cm²
p = 8 + l
l = l
Kp = 40 cm
ditanya : Lp...?
jawab :
Kp = 2(p+l)
40 = 2(8+l+l)
40 = 2(8+2l)
40 = 16 +4l
4l = 40-16
4l = 24
l = 24/4
l = 6 cm
• p = 8 + l
~ p = 8 + 6
~ p = 14 cm
• l = l
~ l = 6 cm
•> Lp = p × l
•> Lp = 14 × 6
•> Lp = 84 cm^2