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You don't mention whether the 4 feet is the circumference, diameter or radius.
The area of a circle is pi times the radius squared.
If 4 feet is the circumference, the area is about 1.3 feet squared.
If 4 feet is the diameter, the area is about 12.6 feet squared.
If 4 feet is the radius, the area is about 50.3 feet squared.
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How do you calculate area under the hydrograph curve without integrating?
Basically this isn't possible. Whenever you have an irregular curve, you need some kind of integration technique to get the area, or an estimate of the area. This can be quite simple, at least in principle: just approximate the area by narrow rectangles, calculate the area of each rectangle, and add everything up.
Why does pi appear in formulae for the circumference and the area of a circle - what is the connection?
Pi is defined as the ratio of the circumference of a circle to its diameter (pi = circumference / diameter). So that explains why it's in the circumference formula. For the area, a little knowledge of calculus is helpful. Here's a 'simple' explanation.Suppose you have a polygon with many sides, which is inscribed into a circle. The area of the polygon can be found by adding up the areas of isosceles triangles formed by a polygon side and line segments extending to the center. If you have enough sides, then the base of each small triangle will approximately be equal to the corresponding arc of the circle. For sufficiently small triangles (a very large number of sides for the polygon), a 'long leg' of the isosceles triangle will be approximately equal to its altitude.Say that we have a 100 sided polygon, with radius R and diameter = 2*R. So lets find the approximate area of the polygon. Each base (polygon side) will be approximately equal to Circumference/100, and each altitude will be approximately equal to R. So the area of one triangle is equal to Base*Altitude/2, which is approximately (Circumference/100)*R/2. Substitute Circumference = pi*Diameter = pi*2*R.Each triangle area is approx (pi*2*R/100)*R/2 = (pi/100)*R2. Since there are 100 triangles, the polygon area is approximately pi*R2 (which is the area of the circle). Note the word approximate, because there is slight space between the polygon and the circle, but [here's the calculus part], as the number of polygon sides approaches infinity, the space between the polygon and the circle approaches zero, and the errors in approximation approach zero, so that the area of the circle and the infinite sided polygonare the same.
A triangle or a square or a rectangle or a pentagon or a hexagon or an octagon or a circle has the least area and which has the maximum area if the perimeter of each is 44 cm?
Triangle-least area, circle- most area, per given perimeter . The circle would have an area of 154 square cm. the triangle could have an area of almost zero if it were a long, skinny triangle. An equilateral triangle would have an area approx 92.8 sq cm.
A square is inscribed in a circle of area 18 PI find a side of a square?
Area of circle: 18pi Radius of circle: square root of 18 = 3 times square root of 2 Using Pythagoras' theorem each side of the square is 6 units in length
What is the radius of a circle that has area of 68 square feet?
Area of circle = pi*r^2 so......... 68 sqr ft = pi * r^2 divide both sides by pi 21.645 = r^2 take square root of each side 4.7 feet = the radius of this circle
