Question

A cylindrical lead pencil has a conical end. If the total height of the pencil 13cm and its radius is 0.7cm, then find the total surface area of the pencil if the height of conical region is 0.9cm. ​

Answer 1

Answer:

A≈30.17cm²

r Radius

0.7

cm

h Height

13

cm

Using the formulas

A=πrl+πr2

l=r2+h2

Solving forA

A=πr(r+h2+r2)=π·0.7·(0.7+132+0.72)≈30.16929cm²