Perbandingan panjang dan lebar persegi panjang 8:5. Jika kelilingnya 78 m, maka luasnya adalah......m*2

Mapel : Matematika
Bab : Bangun datar

p : l = 8 : 5 = 8x : 5x

2(p + l ) = 78
2(8x) + 2(5x) = 78
16x + 10x = 78
26x = 78
x = 78/26
x = 3

p = 8x
p = 8(3)
p = 24 m

l = 5x
l = 5(3)
l = 15 m

L = p × l
L = 24 × 15
L = 360 m^2

P:L = 8:5
Per.K = P+P+L+L / 2x(p+l)
= 8+8+5+5 / 2x(8+5)
= 26
P seb. = 8/26X78m
= 24m
L seb. = 5/26X78m
= 15m
Luas = 24mX15m
= 120m²

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