What is the formula for the surface area of a tetrahedra.?
155419
the base of a triangle times the height times 2\n\nb*h*2
768235
surface area = (2 * pi * r^2) + (2 * pi * r * h)\nh = 5, surface area = 100 (put in units later)\n\n100 = (2 * pi * r^2) + (2 * pi * r * 5)\n2pi*r^2 + 10pi*r - 100 = 0\n\nNow bring in the best equation in the world. (Quadratic Formula)\nx = (-b +- sqrt(b^2 - 4ac)) / 2a\n\nr = (-10pi +- sqrt(100pi^2 + 800pi) / 4pi\n\nThrow the negative out, because length cannot be negative.\n\nr ~ 2.21cm
984888
it would be 2/3 of the original surface area\n\nOriginal Cube Surface Area:\n6 sides.....one side = Length * Width\n6*L*W\n\nIf you cut it exactly in half, you have 2 sides that are still Length * Width, and 4 sides that are HALF Length * width....so u can combine those 4 halves to make 2 wholes and ur surface area will be 4 (Length*Width)'s\n\nmaking it 4/6th of the original surface area\nsimplifying gives u 2/3
63381
Conjecture A\nIf B is the area of the base pf a right rectangular prism and H is the height of the solid, then the formula for the volume is V= _?_\nConjecture B \nIf B is the area of the base of a right prism (or cylinder) and H is the height of the solid, then the formula for the volume is V= _? _\nConjecture C\nThe volume of an oblique prism (or cylinder) is the same as the column of the right prism (or cylinder) that has the same _? _ and the same _? _\nPrism-Cylinder Volume Conjecture\nThe volume of a prism or a cylinder is the _? _ multiplied by the _? _\nPyramid-Cone Volume Conjecture\nIf B is the area of the base of a pyramid or a cone and H is the height of the solid, then the formula for the volume is V= _? _ \nSphere Volume Conjecture\nThe volume of a sphere with radius r is given by the formula _?_\nSphere Surface Area Conjecture\nThe surface area, S, of a sphere with radius r is given by the formula _? _\n\nSolution 47916\n\n#1\nV = BH\n#2\nV = BH\n#3\nsame base area and same height\n#4 \nthe base area multiplies the height\n#5\nV = (1/3)BH\n#6\nV = (4/3)(pi)(r^3)\n#7\nS = 4(pi)(r^2)
784010
Take the formula for the surface area(S) and solve for r\nS=4*pi*r^2\nr^2 = S/(4pi)\nr =squareroot(S/4pi) or (S/4pi)^(1/2)\n\nNow take the formula for the volume\n4/3*pi*r^3\nand substitute the formula for r into the equation\n4/3*pi*(squareroot(S/4pi))^3\n4/3*pi(S/4pi)^(3/2)
67968
It is similar to calculating the area. \n\nIt is a product of Length and Width (L x W).
847764
Surface Area = 4*PI*r^2\n\nr = SQRT(SA/4/PI)
856302
Surface Area = (2 •  p   • r²) + (2 • p  • r • height)\n\nWhere (2 • p • r² ) is the surface area of the "ends" and\n(2 • p • r • height) is the lateral area (the area of the "side").\n\nVolume   =   p • r² • height   =   ¼ • p • d² • height\n\np = Pi
486266
the formula for volume of a cylinder is V = h * pi * r^2.\nAlternatively, the surface area is A = h * pi * r * 2.\n\nSo, if you have either the surface area or the volume, you can calculate for the height.\n\nH = Volume / pi * r^2\nH = Area / pi * r * 2
895037
surface area of a cube is 6a^2\nvolume=a^3\ntheir relation: V/SA = a/6\n\nif its cut into half, volume will be:\n(a/2) x a^2 = (a^3) / 2\nthe surface area will be 2a^2 + 4a(a/2) = 4a^2\nnow their relation: V/SA = a/8\n\nnote: crazy horse's answer went wrong when he assumed a halved cube has only two of its sides halved. in fact, it has its 4 sides halved.
42062
Surface Area of a Sphere = 4 pi r^2\n\nCompute it for 95mm and 130mm and take the difference.
887520
Volume = pi r^2 h \n\nMeasure a Coke can to get r and h and calculate the volume.  Plug it in for V in  the volume formula and solve it for h.\n\nThen take the surface area formula, SA = 2 pi r^2 + 2 pi r h,\nreplace the h with your answer from above, find the first derivative d(SA)/dr, and make it equal to zero to find the minimum.
827739
Not quite sure what you are asking for....\n\nThe surface area of a right cone (i.e. a cone with its vertex above the center of its base) is:\npi*R*sqrt(R^2+H^2)\n\nwhere R is the radius of the base and H is the height of the cone.
193691
area = r^2 * pi\narea = 9.8^2 * 3.1415\narea = 96.04 * 3.1415\narea is about 301.71
559607
A rectangular prism is simply made up of 6 rectangles.  One pair of rectangles would be 3cm x 3cm (the ends).  The other 4 rectangles would be 3cm x 20cm.  So the total surface area would be the sum.\n\n3cm x 3cm = 9 sq. cm\n3cm x 20cm = 60 sq. cm\n\nSo 9 + 9 + 60 + 60 + 60 + 60 = 258 sq. cm.\n\nIn this case two of the dimensions were the same, but if the sides were h,w,l the total surface area would be:\n= hw + hw + hl + hl + lw + lw\n= 2hw + 2hl + 2lw\n= 2 (hw + hl + lw)\n\nIn your example:\n= 2 (3x3 + 3x20 + 3x20)\n= 2 (129)\n= 258 sq. cm.   (Don't forget the units are sq. cm)
890633
1. total area of a box of sides a,b,c is 2(ab+bc+ca)\na=4,b=3,c=6 => surface area = 108 sq.ft\n..\n2.Lateral area = pi*radius*slant ht\npi=3.1415,radius=2m(4m/2), slant ht=15m\nans is 188.49sq.metres\n..\n3.   volume of pyramid = (1/3)* height * base area\n= (1/3)* (6) * (6*6)\n= 72 cu.metre\n..\n4. lateral area of cylinder = 2*pi* radius* height\n=2*3.1415*12*60\n=4523.76cu. mm\n..\n5. total surface area = outer surface + inner surface + top surface + bottom surface\n= 2*pi*8*height + 2*pi*5*height + 2 times ( pi*(8-5)^2)\n[the last term is the sum of top and bottom surfaces which are circular rings]\nheight is not given :(
135768
Area = Pi times the radius squared (A=pr2)\nIf you need to know how to find the radius, go here:\n\nhttp://math.about.com/library/blcircle.htm