5th Year Maths Test: The Circle

What is the equation of the circle with centre (0,0) and radius 5.

• $x^2\ +\ y^2\ =\ 5$

• $x^2\ +\ y^2\ =\ 25$

• $x^2\ +\ y^2\ =\ 15$

• $x^2\ +\ y^2\ =\ 20$

What is the equation of the circle with centre (0,0) and radius 7.

• $x^2+y^2=12$

• $x^2+y^2=7$

• $x^2+y^2=49$

• $x^2+y^2=0$

What is the equation of the circle with centre (2,3) and radius 4.

• $(x-2)^2+(y-3)^2=4$

• $x^2+y^{2\ }=\ 4$

• $(x-2)^2+(y-3)^2=16$

• $x^2+y^{2\ }=\ 16$

What is the equation of the circle with centre (-4,5) and radius 10.

• $(x-4)^2+(y-5)^2=10$

• $(x-4)^2+(y\ +\ 5)^2=100$

• $(x+4)^2+(y-5)^2=10$

• $(x+4)^2+(y-5)^2=100$

 $x^2+y^2=16$  

What is the radius of the circle?

• 16

• 4

• 8

• 2

What is the centre of this circle?

 $x^2+\ y^2\ =\ 144$  

• (0,0)

• (12, 12)

• 144

• 12

 $\left(x+2\right)^2+\left(y-4\right)^2=36$  
What is the value of "h" from the centre (h, k)? 

• 2

• 4

• 36

• -2

Which point(s) lies ON the circle?

• A

• B

• C

• D

What is the length of the radius of this circle?

(a)  

What is the length of the radius of this circle?

(a)