Geometry formulas Algebra

Standard Circle Formula

• Ax^2+By^2+Cx+Dy+E=0

• A+B+C+D+E=0

• (x-h)^2+(y-k)^2=r^2

• (x-h)^2+(y-k)^2=r

General Circle Formula

• Ax^2+By^2+Cx+Dy+E=0

• (x-h)^2+(y-k)^2=r^2

• (x-Z)^2+(y-k)^2=r^2

• Ax^2+By^2+Cx+Dy+E=R^2

Translations

Move UP

(X,Y)→?

• (X+#,Y)

• (X,Y+#)

• (X,Y-- #)

• (X-- #,Y)

Rotations

90 CW or 270 CCW

(X,Y)→?

• (y, -x)

• (-x, y)

• (x, -y)

• (-y, x)

Rotations

90 CCW or 270 CW

(x,y)→

• (-y, x)

• (-x, y)

• (y, -x)

• (x, -y)

Rotations

180 CW or CCW

• Swap x and y

• Swap signs

• Make x negative

• Flip what ever x and y's current signs are now

Reflections

x-axis

• (x, y) to (x, -y)

• (x, y) to (-x, y)

• (x, y) to (-x, -y)

• (-x, y) to (x, -y)

Reflections

across y-axis

• (x, y) to (-x, y)

• (x, y) to (x, -y)

• (x, y) to (x, y)

• (x, y) to (-x, -y)

Reflections

Across y=x

• (x, y) to (y, x)

• (x, y) to (y, -x)

• (x, y) to (-x, -y)

• (x, y) to (-y, x)

Reflections

Across y= -x

• (x, y) to (-y, -x)

• (x, y) to (-y, x)

• (x, y) to (-x, -y)

• (x, y) to (y, -x)