Dik: r=3,5 t=12cm phi= 22/7,,,.... Dit: s=? luas sisi kerucut?

S=√t²+r²
=√12²+3,5²
=√144+12,25
=√156,25
=12,5

Luas sisi kerucut=πrs
=22/7x3,5x12,5
=22/2x12,5
=137.5