11, I believe.
There is no such thing as a three sided rectangle. They have four sides. Length and width of a rectangle being THE SAME (having a 1:1 ratio) will provide the largest area possible. In other words, for a given perimeter, a square is the largest rectangle. If you mean a triangle (which has three sides), then all sides being equal will still yield the largest area.
A 4 by 4 and a 1 by 7.
2
It is 2*r^2.
Apart from a few cases it is not at all easy. You would need to consider all possible cross sections. In most cases the answer will depend on the relative measures of the different sides or edges.A cube, for example, can have a cross section that is a point, line, triangle, square, rectangle, hexagon. The first two can be rejected since they have 0 area. But for the others, you would have to use differential calculus to determine the largest for that shape. It is, in fact, the rectangle from one edge of the cube to the diagonally opposite edge. The area is sqrt(2) times the side length.
Not sure if this is what is required, but the area of the largest square that will fit in a 18 by 9 rectangle is 9 by 9.
The answer depends on what your criterion for deciding what is "largest". Any rectangle will have an area of 47916 square feet. Its perimeter can be infinitely large.
The smallest is just over 40 units. At 40 units it is no longer a rectangle but a square. There is no largest perimeter.
Largest = 86, Smallest 26
Find the dimensions of the rectangle of largest area that can be inscribed in a circle of radius a in C programming
9 by 9
There is no such thing as a three sided rectangle. They have four sides. Length and width of a rectangle being THE SAME (having a 1:1 ratio) will provide the largest area possible. In other words, for a given perimeter, a square is the largest rectangle. If you mean a triangle (which has three sides), then all sides being equal will still yield the largest area.
20 ft
A 4 by 4 and a 1 by 7.
The lumbar vertebrae are the largest segments of the movable part of the vertebral column
If the shapes are similar, such are all circles or all squares, those with the largest perimeters would also have the largest areas. However, in general there is no direct relation. For example a 2 by 2 rectangle has an area of 4 and a perimeter of 8, but a 2000 by 0.0005 rectangle has an area of 1 and a perimeter of 4000.001.
25 cm