Circular area: xRxR Circular perimeter: UxD
Cubic surface area: axax6 Volume: axaxaxa
Rectangular surface area: (axb+bxc+axc)x2 volume axbxh
Cylinder surface area: 2x3. 14xrxr+ xdxh volume: xrxrxh.
Cone volume: 1 3 of Uxrxrxrxhx.
Surface area of sphere = 4 π r 2
The volume formula of the cone is: v= 1/3sh(s is the bottom area of the cone and h is the height of the cone).
The volume formula of prism: V = [S+S'+(SS') (1/2)] h/3.
The truncated cone volume formula: v = [s+s'+√ (ss')] h ÷ 3 = π h (R2+RR+R2)/3.
The formula of frustum surface area is: s = π R2+π r' 2+π rl+π r' l = π (R2+r' 2+rl+r' l).
R- upper bottom radius
R- bottom radius
up level
Prism: base multiplied by height
Ring circumference: outer circumference+inner circumference (πx (major diameter+minor diameter))
Area of circular ring: area of outer circle-area of inner circle (πx long radius square -πx short radius square \πx (long radius square-short radius square))
Expressed in letters:
Internal s+ external s (∏R side)
External s- internal s =∏(R party -r party)
There is a second method:
S=π[(R-r)×(R+r)]
R= radius of great circle
R= radius of small circle