Question

Diketahui luas segitiga ABC pada gambar di samping 66cm^.keliling segitiga ABC adalah...
bd(5cm),cd(12cm)
a.36 cm
b.38cm
c.40cm
d.44cm

Answer 1

Kemungkinan gambarnya ada pd lampiran

BC² = 12² + 5²
BC² = 144 + 25
BC² = 169
BC = √169
BC = 13 cm

L ACD = 66 - (1/2 × 12 × 5)
= 66 - 30
= 36 cm²

AD = (2 × 36) / 12
AD = 6 cm

AC² = 12² + 6²
AC² = 144 + 36
AC² = 180
AC = √180
AC = 13,4 cm

keliling ∆ ABC = AD + BD + BC + AC
= 6 + 5 + 13 + 13,4
= 37,4 cm