Circles Review

What is the standard equation of a circle?

• (x-k)² + (y-h)² = r²

• (x+h)² + (y+k)² = r²

• (x-h)² + (y-k)² = r²

• (k-x)² + (h-y)² = r²

What does (h,k) standard for in the standard circle equation?

• (h,k) is the center of the circle

• (h,k) is a point on the circle.

• (h,k) is a point that we guess and find

• (h,k) is the distance of the circle

What does the r in the standard equation stand for?

• r is the distance of the circle

• r is the radius of the circle

• r is the x coordinate of the center of the circle

• r is the y coordinate of the center of the circle

What is the center and the radius of the circle with equation, (x-4)² + (y-2)² = 25

• Center is (5,2) and radius is 4.

• Center is (2,5) and radius is 4

• Center is (2,4) and radius is 5

• Center is (4, 2) and radius is 5

What is the center and radius of a circle with the equation, (x-1)² + (y-3)² = 4

• Center is (1,3) and radius is 2

• Center is (3,1) and radius is 2

• Center is (3,2) and radius is 1

• Center is (2,3) and radius is 1

What is the circle equation, given the center is (4,1) and the radius is 3?

• (x-4)² + (y-1)² = 9

• (x+4)² + (y+1)² = 9

• (x+1)² + (y+4)² = 9

• (x-1)² + (y-4)² = 9

What is the equation of a circle, given the center is (-2, 3) and the radius is 4?

• (x+2)² + (y-3)² = 2

• (x-2)² + (y+3)² = 16

• (x+2)² + (y-3)² = 16

• (x-2)² + (y-3)² = 2

What is the equation of a circle given the center is (-5,7) with a radius of 5?

• (x-5)² + (y+7)² = 25

• (x+5)² + (y-7)² = 25

• (x-5)² + (y-7)² = 25

• (x+5)² + (y+7)² = 25

Which equation matches the circle on the graph?

• (x-3)²+(y-4)²=16

• (x-5)²+(y-2)²=20

• (x+3)²+(y+4)²=16

• (x-9)²+(y-16)²=32

Which equation matches the circle on the graph?

• (x+2)²+(y+5)²=9

• (x+10)²+(y+5)²=9

• (x+5)²+(y+10)²=81

• (x+5)²+(y+10)²=9