Jika keliling segitiga ABC adalah 36 cm,luasnya adalah...cm^2 a.44 b.54 c.56 d.108 Pakai cara yhaa...

(x+3) + 2x + (2x+3) = 36
x + 2x + 2x = 36 - 3 - 3
5x = 30
x = 30/5
x = 6

(x+3) = (6+3) = 9 cm
2x = 2×6 = 12 cm

L = 9×12:2
L = 54 cm² (b)

semoga membantu

Mapel : Matematika
Kelas : VII SMP
Bab : Bangun Datar

Pembahasan :
Keliling = 36
(x + 3) + 2x + (2x + 3) = 36
5x + 6 = 36
5x = 36 - 6
5x = 30
x = 6

Luas = 1/2 at
Luas = 1/2 x AB x AC
Luas = 1/2 (2x)(x + 3)
Luas = 1/2 (2.6)(6 + 3)
Luas = 1/2 (12)(9)
Luas = 54 cm²

Opsi B.