tentukan luas segitiga yang sisinya 7 cm,8cm&9cm

keliling = 7+8+9 = 24 cm
s = 24/2 = 12 cm

Luas = √12(12-9)(12-8)(12-7)
= √12x3x4x5
= √144x5
= 12√5 cm²

Keliling segitiga = 7+8+9 =24
s =
=[tex] \frac{1}{2} \times 24 = 12[/tex]cm

L=
=[tex] \sqrt{s(s - 7)(s - 8)(s - 9} [/tex]
=[tex] \sqrt{12(12 - 7)(12 - 8)(12 - 9} [/tex]
=[tex] \sqrt{12 \times 5 \times 4 \times 3} [/tex]
=[tex] \sqrt{720} [/tex]
=[tex]12 \sqrt{5} [/tex]cm"