Question

diameter=21cm radius=10.5 then what will circumference of semicircle​

Answer 1

Answer:

circumference of cicle = 2pi r

Step-by-step explanation:

circumference =21×10.5 =220.5 cm

Answer 2

Answer:

Hence, value of circumference of semi circle will be 54 cm

Step-by-step explanation:

In context to question asked,

We have to determine the circumference of semi circle.

As per data given in the question,

We have,

Radius of semi circle = 10.5 cm

As we know that,

Circumference of semi circle is equal to half of circumference of circle plus value of diameter.

So, we have,

Formula for finding the circumference of semi circle as,

$Circumference \:C = (\Pi r + 2r), \\where \:'r' \:is \:the\: radius.$

So, for determining the value of circumference of semi circle we will put the value of radius in above formula.

Thus we will get.

$C = \Pi r +2r \\= \frac{22}{7}\times 10.5 +2\times 10.5\\=>(22 \times 1.5) + 21\\=>33+21 = 54\:cm$