We know what 'pi' is, but what's the ratio of sphere's surface area to its bi-secting cross-section area?
407730
Let's look at the general case. It turns out that for even dimensional spheres, the ratio of the 'surface area' to the 'volume' of the next lower dimensional sphere is irrational in even dimensions and rational in odd dimensions. Your cases are just special cases of this general result.
195921
Pi is 3.14159265 and is the ratio of the circumference of a circle to its diameter\n\nPhi is 1.61803399 and is known as the golden ratio, evident in everything from rose petals, the building of the pyramids and the painting of the mona lisa.
71760
area := Πr2\ncircumference := Πd  ,  r=radius, d=diameter, Π=3.14128....
901347
You could use the formula for surface area of a sphere to solve this.\n\nUsing google, I found the diameter of the earth is 12756.3 km, which is equal to 41,851,378 ft.  So the radius is 20,925,689 ft.\n\nThe formula for surface area of a sphere is 4pi r².\n\nSo the square feet covering the earth is 4pi(20,925,689)² square feet.  \n\nThis is approx. equal to 5.5026 * 10^15 square feet.\n\n~ ♥ ~
1175861
Area of Semicircle = (PI * R * R)/2\n\nAns. = 2.262 sq. cm
310080
Area = pi times radius squared, so divide the diameter by 2 and go from there
1175686
This can be solved in several different ways.  One of course is by calculus, by developing a formula for the surface area of a "slice" of the remainder of the sphere and integrating it about a rotated axis, or something similar.  Another is by digging for the rather obscure formula for the "volume of the endcaps of a sphere" and subtracting two of those and the volume of a cylinder from the volume of the original sphere (and discovering that many of the terms will cancel out nicely).\n\nThe easiest method, however, is via the use of simple logic.  Unfortunately, this method also requires one more "given" in order for it to be valid, though this given is not an unreasonable one:  There must be a single, real answer (or more specifically, a unique answer on the real number line).  Such an assumption would be folly in a practical (real-world) context, since without some form of proof, one should never immediately assume that this is the case.  Perhaps there are multiple answers, or there is no answer at all?  But as luck would have it, there actually is one answer, and it may be derived logically due to its unique existence.  (*thumbs nose at any philosophers who may be reading*)\n\nSolution:\n\nLet R be the radius of the cylinder drilled into the sphere.  If and only if there is a single, real answer, then that answer would still be the same no matter the value of R... even if R=0.  Thus, the answer is the volume of a sphere of radius 3 (diameter 6), or 36*pi cubic units.\n\n(Yes, the volume is always the same, whether the original sphere were the size of a basketball, or the size of a planet.)\n\nIt's a surprising answer, along the lines of the more familiar puzzle: "If the Earth were a perfect sphere and a band were placed snugly about its equator, and then one more meter were added to the length of the band and it were stretched so that all points along it were equidistant from the surface of the Earth, how far above the Earth would the band rise?"  Many are surprised to find that the size of the Earth plays absolutely no part in the equation, and that the "rise" is exactly the same if the sphere were basketball-sized or, umm... Earth-sized (with a circumference greater than 40,000,000 meters).  It rises exactly the radius of a circle with a 1-meter circumference: 1 / (2*pi) meters.
40559
Just what are you asking? \n\nIf this were the Baking section, then you owe someone two pies. \n\nIf you are talking Math (this section), then I presume you are talking about PI (the value used in Circumference = 2 (PI) * radius, Area = PI * r^2, Volume = (1/3) PI * r^3). Following these derivations, I have no clue where PI^5 lies in Geometry.\n\nOr, finally, if you are thinking 3*PI - 5*PI, you get -2 * PI, or -2 * 3.14159..., = -6.28318...
667893
Pi*r^2*h in the first answer is the volume of a cylinder and is rather wrong!\n\nthe surface area of a cone is pi*r*l where l is the slant height of the cone. you need to calculate this from the height and the radius (not the diamteter) by pythagoras.\n\ntaking l=5.707506\nsurface area is 27.344231865 sq metres\nconvert units to cm^2 =273442.31865 sq cm
42062
Surface Area of a Sphere = 4 pi r^2\n\nCompute it for 95mm and 130mm and take the difference.
869293
I expect the answer is surface.\n\nA sphere has circumference, too.  But the thing is that a circle encloses a two-dimensional space, and the circumference is the boundary of that space.  Well, a sphere encloses a three-dimensional space, and the thing that encloses that space is the surface,  or surface area if you're thinking in terms of measure.
691057
Imagine cutting the tube down its length and opening it up into a long, narrow rectangle.  The outside area would be the length times the width.  The width of the rectangle is really the circumference of the circular cross section of the tube.  Thus, since you know the diameter, you have this:\n\nsurface area = length * pi * diameter\n\nwhere pi is approximately 3.14159265358979.\n\nNote, if the tube is not flexible, you have to be careful measuring the length of the bent tube.  it is the length of an imaginary line through the center of the tube, but as the other answerer pointed out, you can get this by taking the average of the "inside the curve" length and the "outside the curve" length.  Of course, if the tube is flexible, just straighten it out and measure it.\n\n\nNote--straightening, cutting and opening up, etc., will change the area slightly as it stretches part of the tube and compresses another part--this is a very small effect (unless you tie the tube into a tight knot or something) and probably can't easily be measured well anyway--should be too small to matter in most applications.
680200
Assuming this means a circle...\n\ndefn/:\n\nc=circurmfernce\nA=area\nr=radius\nd=diameter\npi=pi (~3.1415926...)\nd=2*r\n\nC=2*pi*r=d*pi\nA=pi*(r^2)...(area is pi*r squared...pie are squared-no there not their round).\nA=pi*(d^2)/4.\n\njust plug and chug...\n\nC=10*pi.\nA=25*pi.\n\nanswer:\n\nit's that simple
186995
There is no specific word as far as i know, but we used to use the term "Total Surface Area.'\n\nThere are different formulas for calculating the total surface area depending upon the shape of the three-dimensional figure.  If you could elaborate your question, one can give you an exact answer; or is this enough?
179064
Pi*r*[square root] of r^2+h^2\nin words- Lateral Surface Area of a Cone= Pi times radius times the square root of (radius squared plus height squared)\n\n"Moe, Moe, Moe. how do you like me, how do you like me, Moe, Moe, Moe. Why dontcha like me, nobody likes me, Moe, Moe, Moe....."
887559
Pi is the ratio of circumfarence of circle to the diameter. It is irrational and approximated by 22/7\n\nThis can be defined as 4(tan ^-1 1)
129445
Pi is the ratio of the circumferance of a circle to its diameter.  The following equation is for the area of a circle:    A = pi*r^2\n\nThe Math Forum website has a very complete and east-to-understand explanation.