Find the curved surface area, total surface area,and volume of a cone whose height is 28cm and radius of base is 21cm About the author Bella
Answer: Given, height of cone (h)=28cm. Radius of base (r)=21cm Slant height of the cone l=r2+h2 Curved surface area =(21)2+(28)2=441+784=1225=35×35=35cm=πrl=722×21×35=2310cm2 Total surface area of the cone =πr(l+r)=722×21(35+21)=22×3×56=3696cm2 Volume of the cone =31πr2h =31×722×21×21×28 =12936 cm Reply
Answer:
Given, height of cone (h)=28cm.
Radius of base (r)=21cm
Slant height of the cone l=r2+h2
Curved surface area =(21)2+(28)2=441+784=1225=35×35=35cm=πrl=722×21×35=2310cm2
Total surface area of the cone
=πr(l+r)=722×21(35+21)=22×3×56=3696cm2
Volume of the cone =31πr2h
=31×722×21×21×28
=12936 cm