Question

The circumference of circle is 42cm.
Find the radius of the circle and area
of the circle​

Answer 1

Answer:

Radius = 6.7cm

Area = 141cm²

Step-by-step explanation:

circumference = 2πr=42

πr= 21

r= 21/π

r= 6.7cm

Area = πr² = π x 6.7x 6.7= 141cm²

Answer 2

Step-by-step explanation:

Answer:-

Given that:-

• Circumference is 42 cm
• We need the RADIUS
• We need the area

Concept:-

Surface area, 2D figures

Let's Do!

Perimeter = 2 × pi × r

$42 = 2 \times \frac{22}{7} \times r$

$\dfrac{42 \times 7}{2 \times 22} = r$

Radius = 6.681 cm.

Now, Area = pi × r²

$\dfrac{22}{7} \times \dfrac{42 \times 7}{2 \times 22} \times \dfrac{42 \times 7}{2 \times 22}$

DID nothing, just replaced the values.

So, the required area is 140.31 cm².

• Keep a special vigil on units.
• If not, convert and solve them.
• Use simplification before decimal conversion.
• In the area, I used the RADIUS 1st value, and the calculation was made super easy.

Edit - r^2 was done, value of answer changed.