The length of a rectangle?
366751
make x the width, and solve the two equations (the one given, and the one assumed about the rectangle where l*w=A)
440729
Try this:\nAssuming the rectangle is centered within the half circle, draw a line from the center of the flat edge of the half circle (should also be the center of one edge of the rectangle) to one of the corners of the rectangle that is touching the edge of the circle.  That line has a length equal to the radius of 10.  By drawing this line you have also formed a 30-60-90 triangle inside the rectangle.  So, the triangle you have just created has a hypotenuse equal to 10 but the sides are unknown.  However, knowing that a 30-60-90 triangle has sides with a relationship of 1, 2, square root of 3, we use the method of similar triangles to  solve for the sides.  The shortest side of the 30-60-90 triangle is thus equal to 5 (this is also equal to the width of the rectangle), the other side is equal to 5*square root of 3 (the length of the rectangle will be two times this value), and the hypotenuse is 10. So the width of the rectangle is 5 and the length is 10*square root 3, so the area of the rectangle is 50*square root 3=86.6
328495
now, if you add that it has 4 sides and all right angles, you probably can pass that off as the definition of a rectangle.\n\notherwise you just have a parallelogram.
501756
length x width = area\n3 x 6 = 18
507349
In geometry, a rectangle is defined as a quadrilateral polygon in which all four angles are right angles.\n\nFrom this definition, it follows that a rectangle has two pairs of opposite sides of equal length; that is, a rectangle is a parallelogram. A square is a special kind of rectangle where all four sides have equal length; that is, a square is both a rectangle and a rhombus. A rectangle that is not a square is colloquially known as an oblong.\n\nOf the two opposite pairs of sides in a rectangle, the length of the longer side is called the length of the rectangle, and the length of the shorter side is called the width. The area of a rectangle is the product of its length and its width; in symbols, A = lw. For example, the area of a rectangle with a length of 5 and a width of 4 would be 20, because 5 × 4 = 20. See the picture above right.
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If an object is a parallelogram, we define its area to be its length multiplied by its height. Rectangles and squares are common parallelograms.\nIf you cut a parallelogram in half along its diagonal, you get a triangle with the same width and height, but half the area. Thus the formula for the area of a triangle is (1/2)*base*height where the name "base" has replaced the now meaningless label of "length".\nUsing these two formulas, you should be able to find the area of any polygon (a closed shape with straight sides) by cutting it up into these shapes of known area. For example, a trapezoid can be cut up into a rectangle and two triangles.\nThe perimeter of a polygon is the easiest measure. Just add up the lengths of all the sides.
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Well, a rectangle is not a triangle it is a parallelogram, I think. It has four right angles and two long sided and two short sides. Therefore, the dimensions are as follows: To figure area it is short side * long side. To figure how long all sides are you simply do two short sides plus two long sides. However, I am assuming that this was trick question to see who is paying attention to what a rectangle is.
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The first area to be defined was the obvious one of a rectangle.  The number of squares of unit size that would fill up a rectangle is clearly the number of such squares that fit in a row across one dimension of the rectangle, times the number of such rows needed.  Since each square has a length and width of one unit, it's easy to see that the length x width = area of a rectangle.\n\nA rectangle can be divided into two right triangles of equal size.  Hence, the area of a right triangle is 1/2 x length x width, only in triangles we call those things base and height.  Now, any arbitrary triangle can be broken up into two right triangles.  Doing so, it's easy to show that the area of *any* triangle is 1/2 x base x height, where the height is defined as the perpendicular distance from the line containing the base to the opposite vertex.  Similar techniques using triangles can be used to find the area of other regular polygons. \n\nThe area of things like circles can be computed from integral calculus, although I suspect there is probably a geometric method to find the area of a circle as well.\n\nThe area of figures bounded by more complex functions than straight lines and circles is found using integral calculus.
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Area of a rectangle formula\n\nA = LW\n\nA = 4 x 5\n\nA = 20 Square feet\n\nThe answer is A = 20\n\n- - - - - - - - - -s-
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a: width\nb: length\nperimeter = 2 x (a+b)= 420 ---> a+b = 210\nwe need to find max (a x b)\n\na= 210-b ---> area = a x b = b x (210-b) = 210 - b2 = - b2 + 210b = - b2 + 2 x 105 x b - 105squared + 105squared\n= - (b2 - 2 x 105 x b + 105squared) + 105 squared\n= - (b - 105)squared + 11025\n\nSince (b - 105) squared is always >= 0,\n - (b - 105)squared is always <= 0\n  - (b - 105)squared + 11025 is always  <= 11025\n\nthe largest area will be 11025 squared feet. This happens when - (b - 105)squared = 0, which means b = 105.\n\na = 210 - b = 105\n\n\nthe shortest way is to say that a rectangle has the largest area when it's a square, so each side would be 420/4 = 105.
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length x width (in inches)\n\ndivide by 12 ( feet)
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I don't know how these could be the sides of a rectangle since rectangles have two dimensions, not 3.  And if you mean a rectangular prism (box) none of these are invalid as dimensions.\n\nI think you mean triangle and the answers are 3,4 and 7 as well as 3,5 and 9 because that would result in triangles with no area.  \n\nThe sum of the shorter sides should always be more than the third side.  The only one that meets those criteria is #1.  \n\n#1:  2+3 > 5 --> good triangle\n#2:  3+4 = 7 --> bad triangle (flat)\n#3:  3+5 < 9 --> bad triangle (impossible)\n\nSo #2 and #3 are not the sides of a valid triangle.
354751
Find the circumference: 2 X 3.14 X 3\n\nThe lateral area is exactly like the area of a rectangle, so the width of the rectangle=circumference.\n\nCirc X 4 (height) = 75.36
813209
perimeter= 4(L+W+H)\narea= length times the width times the height
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(x+4)(2x+4)-2x^2=88\n2x^2+12x+16-2x^2=88\n12x+16=88\nadding -16\n12x=72\ndividing by 12\nx=6\nso the dimensions of the original rectangle are  6m*12m
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http://www.onlineconversion.com/length_common.htm
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let area be A\nwidth be W\nlength be L\nnow area of rectangle is = length * breadth \n    A = L * B\n  L = A/B\n L = 3x (squared) +14x+8 / x+4\n   = (3x+2)(x+4) / (x+4)\n   = 3x+2