Answers OH-Geometry BSpecial Parallelograms

Special Parallelograms — Unit test Answers

0 verified answers

In the diagram, a circle centered at the origin, a right triangle, and the Pythagorean theorem are used to derive the equation of a circle, x2 + y2 = r2.

(h + x)2 + (k + y)2 = r2

(x – h)2 + (y – k)2 = r2

(k + x)2 + (h + y)2 = r2

(x – k)2 + (y – h)2 = r2

Free Preview

On a coordinate plane, a circle has a center at (1, negative 2) and a radius of 4 units.

(x – 1)2 + (y + 1)2 = 16

(x – 1)2 + (y + 1)2 = 4

(x + 1)2 + (y –1)2 = 4

(x + 1)2 + (y – 1)2 = 16

What is the center of a circle whose equation is x2 + y2 – 12x – 2y + 12 = 0?

(–12, –2)

(–6, –1)

(6, 1)

(12, 2)

What is the center of a circle whose equation is x2 + y2 + 4x – 8y + 11 = 0?

(–2, 4)

(–4, 8)

(2, –4)

(4, –8)

What is the center of a circle represented by the equation (x+9)2+(y−6)2=102?

(−9,6)

(−6,9)

(6,−9)

(9,−6)

Which point is on the circle centered at the origin with a radius of 5 units?Distance formula:

(2, )

(2, )

(2, 1)

(2, 3)

Mrs. Culland is finding the center of a circle whose equation is x2 + y2 + 6x + 4y – 3 = 0 by completing the square. Her work is shown.x2 + y2 + 6x + 4y – 3 = 0x2 + 6x + y2 + 4y – 3 = 0(x2 + 6x) + (y2 + 4y) = 3(x2 + 6x + 9) + (y2 + 4y + 4) = 3 + 9 + 4

(x – 3)2 + (y – 2)2 = 42, so the center is (3, 2).

(x + 3)2 + (y + 2)2 = 42, so the center is (3, 2).

(x – 3)2 + (y – 2)2 = 42, so the center is (–3, –2).

(x + 3)2 + (y + 2)2 = 42, so the center is (–3, –2).

Which equation represents a circle with a center at (–3, –5) and a radius of 6 units?

(x – 3)2 + (y – 5)2 = 6

(x – 3)2 + (y – 5)2 = 36

(x + 3)2 + (y + 5)2 = 6

(x + 3)2 + (y + 5)2 = 36

Which equation represents a circle that contains the point (–2, 8) and has a center at (4, 0)?Distance formula:

(x – 4)2 + y2 = 100

(x – 4)2 + y2 = 10

x2 + (y – 4)² = 10

x2 + (y – 4)² = 100

Which explains how to find the radius of a circle whose equation is in the form x2 + y2 = z?

The radius is the constant term, z.

The radius is the constant term, z, divided by 2.

The radius is the square root of the constant term, z.

The radius is the square of the constant term, z.

Did you find these answers helpful?

Special Parallelograms — Unit test Answers

More from this Course

TRY EDGENUITY HACKS