Question

The sum of the circumferences and diameter of a circle is 116cm . Find its radius.

pls solve this on any notebook​

Answer 1

$\sf\small\underline\red{Given:-}$

$\sf{\implies Sum\:_{(circumference+diameter)}=116}$

$\sf\small\underline\red{To\: Find:-}$

$\sf{\implies Radius\:of\:_{(circle)}=?}$

$\sf\small\underline\red{Solution:-}$

By applying formula to calculate the radius of circle as we know that diameter of circle is 2r and circumference of circle is 2πr.

$\sf\small\underline\red{Formula\:used:-}$

$\sf\longrightarrow{Circumference\:_{(circle)}=2\pi\:r}$

$\sf\longrightarrow{Diameter\:_{(circle)}=2r}$

$\bf{\implies Circle\:_{(circumference)}+Circle\:_{(diameter)}}$

$\tt{\implies 2\pi\:r+2r=116}$

$\tt{\implies 2r(\pi+1)=116}$

$\tt{\implies 2r(\frac{22}{7}+1)=116}$

$\tt{\implies r(\frac{22+7}{7})=116\div\:2}$

$\tt{\implies \dfrac{29r}{7}=58}$

$\tt{\implies r=7\times\:2}$

$\tt{\implies r=14\:cm}$

$\sf\large{Hence,}$

$\bf{\implies Radius\:of\:_{(circle)}=14\:cm}$

Answer 2

Question :

The sum of the circumferences and diameter of a circle is 116cm . Find its radius.

Formulas :

●Circumference of circle = 2πr

●Diameter of circle = 2r

Solution :

Circumference + diameter = 116

$\tt \implies$ 2πr + 2r = 116

$\tt \implies$ 2r(π+1) =116

$\tt \implies$ r($\tt \frac{22}{7}$ + 1 ) = $\tt \frac{116}{2}$

$\tt \implies$ r($\tt \frac{22+7}{7}$) = 58

$\tt \implies$ r = 58 × $\tt \frac{7}{29}$

$\tt \implies$ r = 2 × 7

$\tt \implies$ r = 14 cm

$\tt \therefore$ Radius of circle is 14 cm