The senior high school entrance examination network has compiled junior high school mathematics formulas: the standard equation and formula of circle, hoping to be helpful to the students and for reference only.

The standard equation of a circle: (x-a)2+(y-b)2=r2 Note: (a, b) is the center coordinate.

General equation of circle: x2+y2+Dx+Ey+F=0 Note: D2+E2-4f > 0

Parabolic standard equation: y2 = 2px2 =-2px2 = 2px2 =-2py.

Lateral area of a straight prism: S=c*h lateral area of an oblique prism s = c' * h.

Lateral area of the regular pyramid: S= 1/2c*h' lateral area of the regular pyramid S= 1/2(c+c')h'

Area of frustum side: S = 1/2(c+c')l = pi(R+R)l Surface area of the ball S=4pi*r2.

Cylindrical lateral area: S=c*h=2pi*h Conical lateral area s =1/2 * c * l = pi * r * l.

Arc length formula: l=a*r a is the radian number of the central angle r>0 Sector area formula S =1/2 * L * R.

Cone volume formula: V= 1/3*S*H Cone volume formula V= 1/3*pi*r2h.

Oblique prism volume: V=S'L Note: where s' is the straight cross-sectional area and l is the side length.

Cylinder volume formula: V=s*h Cylinder V=pi*r2h.