Question

find the are of a regular pentagon whose each side is 5 cm.long and the radius Inscribed circle is 3.5​

Answer 1

Answer:

ok

Step-by-step explanation:

the area will be 77 sq cm

Answer 2

To find : area of regular pentagon .

Given : side of pentagon = $5\ cm$ and

             radius of circle inscribed = $3.5 \ cm$

Solution :  

• As we know that area of pentagon is given by :  
• $Area \ of \ pentagon = 5 \times area \ of \ triangle$
• Therefore, divide pentagon into five triangles.

• We take base as $5\ cm$. and height as radius i.e. $3.5 \ cm$  

• .Now , area of triangle = $\frac{1}{2}\times base\times height$

                                             $= \frac{1}{2}\times 5cm\times 3.5cm$  

                                               $= 8.75 \ cm^{2}$

• Now , area of pentagon is,

       $Area \ of \ pentagon = 5 \times area \ of \ triangle$

                                     $= 5\times 8.75\ sq. cm$

                                     $= 43.75 \ sq.cm$

Hence , area of pentagon is $43.75 \ cm^{2}$.