Question

Help me please
Answer Correctly
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Answer 1

Solution:-

The given equation is :-

=> x²+y²+4x-20y+100=0

This is of the form of

=> x²+y²+2gx+2fy+c=0

Where

2g=4 ,2f= -20 and c=100

Now , we get :-

g=2 , f= -10 and c= 100

Hence, the given equation represent a circle

Centre of circle is =(-g,-f)=(-2,10)

Radius of the circle is

$\sqrt{g {}^{2} + {f}^{2} - c }$

$\sqrt{(2) {}^{2} + ( - 10) {}^{2} - 100 }$

$\sqrt{4 + 100 - 100}$

$\sqrt{4} = 2$

Radius=2 unit

i) Circumference of circle is=

$2\pi \: r$

R= 2 units

$c = 2 \times \frac{22}{7} \times 2$

$c = \frac{88}{7}$

$c = 12.57 \: unit$

ii) Area of circle is

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

R=2, so we get

$\frac{22}{7} \times 2 \times 2$

Area of circle is 12.57 unit

Answer:-(i) Center=(-2,10)

(ii) Radius=2 units

(iii) Area=12.57 units

(iv)Circumference =12.57units

Answer 2

Answer:

Area of circle is 12.57 unit

Answer:-(i) Center=(-2,10)

(ii) Radius=2 units

(iii) Area=12.57 units

(iv)Circumference =12.57units