permisi gan ...carikan lah luas dan keliling dari gambar segitiga diatas

S = 1/2×(s1+s2+s3)
= 1/2×(8+7+3)
= 1/2×18
= 9 cm
Luas = akar [ S×(S-s1)×(S-s2)×(S-s3)]
= akar [ 9×(9-8)×(9-7)×(9-3) ]
= akar [ 9×1×2×6 ]
= akar 108
= akar (36×3)
= [ 6 akar 3 ] cm^2
Keliling = s1 + s2 + s3
= 8 + 7 + 3
= 18 cm