Question 17

loading...

Prev/Next links

Jambmaths question: 

Find the curved surface area of a cone with circular base diameter 10cm and height 12cm

Option A: 

25πcm2

Option B: 

120πcm2

Option C: 

156πcm2

Option D: 

65πcm2

Jamb Maths Solution: 

$\begin{align}  & r=\frac{d}{2}=\frac{10}{2}cm=5cm \\ & h=12cm \\ & {{l}^{2}}={{h}^{2}}+{{r}^{2}}\text{   (pythagoras theorem }\!\!\}\!\!\text{ } \\ & {{l}^{2}}={{12}^{2}}+{{5}^{2}}=169 \\ & A=\pi rl \\ & A=\pi (13\times 5)=65\pi c{{m}^{2}} \\\end{align}$

Jamb Maths Topic: 
Year of Exam: