i have to cut an arch into a piece of plywood how do i figure it?
337181
Does this arch need to follow a specific shape? Is it part of a circle? Part of an ellipse? Do you just need a nice bow shape?\n\nCircle or part of a circle = a stick, a nail and a pencil Use the nail in one end of the stick as a center and notch the other end to hole the pencil.\n\nBow = a piece of thin wood (like a piece of lath), a string and a pencil. Use the string to make a bow (like a bow and arrow), then trace the arch.\n\nEllipse = mathforum.org/library/drmath/sets/select/dm_ellipse.html
153204
You can build your shelf by making a visit to your local Home Depot and ordering a few sheets of 3/4 inch plywood and some finishing nails. If you have time, you can attend one of the DIY seminars that they offer; if not, look for shelf plans on the internet.\n\nGood luck!\n\nP.S. Learn to spell check, idiot!
790516
Draw the diagram\n\nLet the height of the tree be h ft and the closer (ie the one with angle of elevation to tree of 35°) be x ft away from the tree\nThus the other is (200 - x) ft away\n\nThen cot 35° = x/h\nie x = hcot 35°\n\nAlso cot 30° = (200 - x)/h\nso 200 - x = hcot 30°\nie x = 200 - hcot 30°\n\nTherefore hcot 35° = 200 - hcot 30°\nie h(cot35° + cot 30°) = 200\nSo h = 200/(cot 30° + cot 35°)\n≈ 63.29 ft
480285
I would  use 3/4" marine plywood. I would also seal any edges that I cut.
93491
shape it into a brick divide its mass by its volume
855656
I'm assuming you're talking about cutting a circle into quadrants? This might be the long way to do it, but I would first find the center of the circle. Here's a web page for how to do that:\n\nhttp://www.makeitsolar.com/science-fair-ideas/90-find-circle-center.htm\n\nThen you draw your diameter. (there's half)\n\nFinally, find and draw a line perpendicular to your diameter that crosses through the center of the circle.\n\nLike I said - probably the long way to do it, but I'm a very visual person when it comes to geometry. I like to draw everything out.
436114
well, you could be an architect and be using a 30-60-90 triangle and you needed to know a particular side of it. you can use x times the square root of 3, x being the shorter leg, to find the length of the longer leg.
41820
I would just measure it, cut the measurement in half for your radius, then set your geometry set or watever to that radius. Draw the circle, drill a hole in the circle and cut with a jigsaw. Then make sure the hole is snug, and use silicon for sealant ( may need stronger if it is enclosed )
918584
How big should this be?\n\nWell, you want to make it slightly arched with a flat road.\nAll triangles for the joints.\n\n.______\n/&#92;/&#92;/&#92;/&#92;/&#92;/&#92;/&#92;
238652
Assuming you have a rectangular object, then L x H x W will work. For other shapes you need something else. See sources.
839189
The required depth = 0.3536m, or about 35.4cm\n\nThis can be solved with or without reference to the angle between the trough sides. The volume V = 6 A where A is the area of a triangular end. So we just have to find when A is a maximum.\n\nA = b*h/2 (where h is the required depth)\n\nAlso, b = 2*sqrt(0.5^2 - h^2)\n\nso A = h*sqrt(0.5^2 -h^2)\n\nNow find h, such that: dA/dh =0\n\nor, more simply:\n\nThe angle betwen the 2 pieces which maximizes the volume is 90 degrees(see footnote). Once you know this you can determine h since h = 0.5*cos(45) = 0.3526\n\nFootnote: Express the the end area in terms of the angle between the 2 pieces of wood. Use the area formula: A = (1/2)a*b*sin(x) where x is the angle between the two pieces. In your case, a=b= 0.5m and so  A = 0.5*0.5*sin(x)/2 = 0.125sin(x).\nSo the volume V=  6*0.125*sinx(x) = 0.75sin(x) cubic m. This will be a maximum when x = 90 degrees since we know the sine function value is a maximum when x=90 degrees, but formally:\n\ndV/dx = 0.75 d/dx sin(x) = 0.75cos(x)=0 when cos(x) =0 when x = 90degrees\nMax volume = 0.75sin(90) = 0.75 m^3
1073101
diagram it out\n\nFOIL  First  Outer Inner Last
1047567
If you have access to AutoCAD there is an option to Hatch (command: H)  In here you can pick various material symbols.  Otherwise, draw lines in your box to look like the cross section of wood.  glass, usually draw two or three diagonal lines  to represent a reflection, and brick is a slightly dense 45 degree diagonal.  Hope this helps.
826815
Conduit Bender. Take the measurements, allow for the arch, and bend.
237985
Cut a 2x2 piece off. Cut the remaining 2x3 piece in half lengthwise.  Put the two resulting 1x3 pieces one atop the other and cut the stack diagonally.  You now have 4 triangles with sides = 1, 3 and sqrt(10).  Arrange them with their right angles touching the corners of the 2x2 square piece, 3-meter sides parallel to and touching the sides of the square piece, and all "pointing" in the same direction, clockwise or counterclockwise.  The result is a square that is sqrt(10) on a side.  Area = 2x5 = sqrt(10)^2 = 10 square meters.  Three cuts were used to make five pieces.\nTo solve this I started with the requirement of the large square being sqrt(10) on a side.  Sqrt(anything) suggests the hypotenuse of a right triangle.  A little mental fiddling produced the sides of 1 and 3 meters.  Luckily a 2x2 piece remained.
621712
to give strength to the plywood. to see an example go to the hobby shop and buy some balsa wood and try it at home. you will find that the wood bends with the grain very easy and fractures but by putting the grain 90 degrees it will support each other when you try to bend it.
1030296
for it to be a triangle the angles have to measure to 180, so if you have a 90 degree andlge off one, you could subtract 90 from that, take the remaining 90 and work with that, since you know your need a 1:1 of the legs , then you know you need an equal angle.. angle has to equal 90/2... and thats where i get stumped...\n      gl