# Mensuration-38

### From Homeworkwiki

**Find the area of the curved surface and total surface area of the cone whose height is 8 cm,**

**and whose base diameter is 12 cm.**

**Solution:** Here, r = 6 cm, h = 8 cm

Therefore, Slant height l = √(h^{2} + r^{2})

= √(8^{2} + 6^{2}) = √(64 + 36) = √100 = 10 cm

Therefore, curved surface area = Π r l = Π (6 x 10) cm^{2} = 60 Π cm^{2}

= 60 x 3.142 = 188.52 cm^{2}

Total surface area = Π r l + Π r^{2} = Π r (l + r)

= Π x 6 x (10 + 6) cm^{2} = 96 Π cm^{2}

= 96 x 3.142 cm^{2}

= 301.63 cm^{2}