Question : The area of the sector of a circle is 128 cm2. If the length of the arc of that sector is 64 cm, then find the radius of the circle.
Option 1: 4 cm
Option 2: 8 cm
Option 3: 2 cm
Option 4: 16 cm
Correct Answer: 4 cm
Solution :
Length of arc = $\frac{ \theta}{360°}\times 2\pi r = 64$
⇒ $\frac{ \theta}{360°} = \frac{64}{2 \pi r}$
Area of the sector = $\frac{\theta}{360°} \times \pi r^2$
⇒ $\frac{\theta}{360°} \times \pi r^2 = 128$
⇒ $\frac{64}{2 \pi r} \times \pi r^2 = 128$
⇒ $r = \frac{128\times 2}{64}$
⇒ $r$ = 4 cm
Hence, the correct answer is 4 cm.
Related Questions
Know More about
Staff Selection Commission Sub Inspector ...
Result | Eligibility | Application | Selection Process | Cutoff | Admit Card | Preparation Tips
Get Updates Brochure
Your Staff Selection Commission Sub Inspector Exam brochure has been successfully mailed to your registered email id “”.
