Question

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Answer 1

$\bold\color{plum}\tt \: Answer \: \: 1 :$

Diameter = 4 cm

Radius = Diameter/2 = 2 cm

Area of circle :

$= \pi{r}^{2}$

$= 3.14 \times 2 \times 2$

$= 3.14 \times 4$

$= 12.56 \: {cm}^{2}$

Circumference of circle :

$= 2\pi r$

$= 2 \times 3.14 \times 2$

$= 12.56 \: \: {cm}^{2}$

Therefore,

Diameter = 4 cm

Radius = 2 cm

Area = 12.56 cm²

Circumference = 12.56 cm

$\bold{\color{plum}\tt \: Answer \: \: 2 :}$

Circumference = 15 feet (given)

Radius :

$= 2\pi r$

$= 2 \times \frac{22}{7} \times r = 15$

$= \frac{44}{7} \times r = 15$

$= 44r = 15 \times 7$

$= 44r = 105$

$= r = \frac{105}{44}$

$= r = 2.38 \: feet$

Diameter = r×2 = 2.38 × 2 = 4.76 feet

Area :

$= \pi {r}^{2}$

$= 3.14 \times 2.38 \times 2.38$

$= 17.78 \: {ft}^{2}$

Therefore,

Diameter = 4.76 feet

Radius = 2.38 feet

Area = 17.78 ft²

Circumference = 15 feet

$\color{plum}\tt \: Answer \: \: 3 :$

Diameter = 2 cm (given)

Radius = D/2 = 2/2 = 1 cm

Circumference :

$= 2 \pi r$

$= 2 \times 3.14 \times 1$

$= 6.28 \: feet$

Area :

$= \pi {r}^{2}$

$= 3.14 \times 1 \times 1$

$= 3.14 \: {ft}^{2}$

Therefore,

Diameter = 2 cm

Radius = 1 cm

Area = 3.14 ft²

Circumference = 6.28 feet

$\color{plum}\tt \: Answer \: \: 4 :$

Radius = 4.3 mm

Diameter = r×2 = 4.3 × 2 = 8.6 mm

Circumference :

$= 2\pi r$

$= 2 \times 3.14 \times 4.3$

$= 27 \: mm$

Area :

$= \pi {r}^{2}$

$= 3.14 \times 4.3 \times 4.3$

$= 3.14 \times 18.49$

$= 58.05 \: {mm}^{2}$

Therefore,

Diameter = 8.6 mm

Radius = 4.3 mm

Area = 58.95 mm²

Circumference = 27 mm