Question

radius = 5 cm
Find the area of the following circles, given that:​

Answer 1

Step-by-step explanation:

area ofthe given circle =

$\pi {r}^{2}$

$= 3.14 \times {5}^{2}$

$= 3.14 \times 25$

$= 78.5{cm}^{2}$

Answer 2

Answer :

The area of the circle is 78.58 cm²

Step-by-step explanation :

To Find,

• Area of the circle ..... (?)

Given that,

• Radius of the circle is 5cm

Figure,

$\setlength{\unitlength}{1cm}\begin{picture}(0,0)\thicklines\qbezier(2.3,0)(2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,-2.121)(0,-2.3)\qbezier(2.3,0)(2.121,-2.121)(-0,-2.3)\put(0,0){\line(1,0){2.3}}\put(0.5,0.3){\bf\large 5\ cm}\end{picture}$

Solution,

We know that,

Area of the circle = πr²

Therefore, by putting the values,

$\mapsto \: \: \: \: \: \: \: \sf{ \dfrac{22}{7} \times {(5)}^{2} }$

$\mapsto \: \: \: \: \: \: \: \sf{ \dfrac{22}{7} \times 25}$

$\mapsto \: \: \: \: \: \: \: \sf{ \dfrac{22 \times 25}{7}}$

$\mapsto \: \: \: \: \: \: \: \sf{ \dfrac{550}{7}}$

$\mapsto \: \: \: \: \: \: \: \bf{78.571428571} \: \: \sf{or} \: \: \bf{78.58 \approx}$

∴ The area of the circle is 78.58 cm²

Some more important formulas of circle

• Circumference = 2πr
• Area = πr²
• Diameter = 2 × Radius
• Radius = Diameter / 2
• Area of a circular ring = π(R² + r² )