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For a square of side a, the area is simple: a2. The perimeter is 4a. How do you deal with a circle, of diameter a? It's obviously less than a2. It turns out to be pi/4 times a2. Or pi times radius squared where pi has been worked out to be 3.1415..... As for angle, for lots of applications it appears a good way of measuring angle by using the length of a piece of circumference of a circle divided by the radius. The units for this is radians. A length of circumference equal to the circle radius gives an angle of 1 in these units when you draw straight lines from the ends of this bit of circumference to the centre. So the whole way around the circle (360o) then is 2.pi.r divided br r, radians, which is just 2 pi radians.
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Area of a part of circle?
Area of a sector of a circle = (pi) x (radius)2 x (central angle of the sector / 360)
What is the area of a sector of a circle with central angle is 18.0 and radius is 5 inches?
The area of the whole circle is pi*r2 = 25*pi To go any further, you need to assume that the central angle is given in degrees. If the sector is 18.0 degrees out of a circle of 360 degrees so the sector represents 18/360 = 1/20 of the whole circle. The area of the sector, therefore, is 1/20 of the area of the whole circle = 25*pi/20 = 5*pi/4 or 1.25*pi = 12.566 sq inches.
The area of the sector formed by the 110 degree central angle is 40 units squared What is the radius of the circle?
measure of central angle/360 degrees = area of sector/area of circle 110 degrees/360 degrees = 40 unit2/ pi r2 unit2 11/36 = 40/pi r2 11 pi r2 = 40 x 36 11 pi r2 = 1,440 r2 = 1,440/11 pi r = square root of 1,440/11 pi r = 20.3 unit approximately
How would you convert an angle in degrees to angle in radians?
Divide the angle measured in degrees by (180/pi). Alternatively, multiply by (pi/180).
Surface area of elbow?
The formula for the surface area of an elbow (or 90° angle) is (pi^2 * (radius2^2 - radius1^2) ) / 4. Where pi = 3.14159, radius 2 = the radius from the center to the outside, and radius 1 = the radius from the center to the inside.
How do you work out the area of a sector using the angle and radius?
the area of a sector = (angle)/360 x PI x radius x radius pi r squared
What is the hypotenuse of pi r squared?
The hypotenuse is the longest side of a right angle triangle The area of a circle is pi*radius2
What is area to the nearest tenth of a 120 degree sector of a circle with radius of 8 ft?
Area of whole circle = pi*r2 = 64*pi Area of Sector = Area of Whole Circle * Angle of Sector/Angle of Whole Circle = Area of Whole Circle * 120/360 = Area of Whole Circle / 3 = 64*pi/3 = 67.0 to the nearest tenth.
What are different kinds of angle differentiate each angle?
Acute angle in the range (0, pi/2) radians = (0, 90) degrees.Right angle = pi/2 radians = 90 degrees.Obtuse angle in the range (pi/2, pi) radians = (90, 180) degrees.Straight angle = pi radians = 180 degrees.Reflex angle in the range (pi, 2*pi) radians = (180, 360) degrees.Full turn = 2*pi radians = 360 degrees.
Find area of a semi circle with angle in degree?
The area is 0.5*pi*r2 where r is the radius. The angle is totally irrelevant since it will always by 180 degrees for a semicircle!
In circle O the area of the sector with central angle AOB is 30 pi cm squared and radius OA is 6 cm. What is the angle measure of arc AB and the length of AB?
The area of the whole circle is PI x 6 squared which equals 36 PI. We can now use the ratio 30/36 = x/360 to find the angle (360 is the full angle if the circle, x is the angle of the segment, pi's cancell out) If we solve for x we get 300 degrees which is the angle we need. As for the length, the circles circumference is 12 PI (12 is the diameter). This means that 30/36= AB/12PI AB=10PI
How do you find the area of a shaded region in a circle?
(pi * radius squared) * ( sector angle / 360 )
How do you find an area of a sector of a circle?
Multiply ( pi R2 ) by [ (angle included in the sector) / 360 ].
What is the area of a sector with a radius of 8 and an arc angle of 80 degrees?
Area = r2*A where A is the angle measure in radians. = 8*8*80*pi/180 = 89.361 square units.
Area of a part of circle?
Area of a sector of a circle = (pi) x (radius)2 x (central angle of the sector / 360)
What is the area of a sector of a circle with central angle is 18.0 and radius is 5 inches?
The area of the whole circle is pi*r2 = 25*pi To go any further, you need to assume that the central angle is given in degrees. If the sector is 18.0 degrees out of a circle of 360 degrees so the sector represents 18/360 = 1/20 of the whole circle. The area of the sector, therefore, is 1/20 of the area of the whole circle = 25*pi/20 = 5*pi/4 or 1.25*pi = 12.566 sq inches.
The area of the sector formed by the 110 degree central angle is 40 units squared What is the radius of the circle?
measure of central angle/360 degrees = area of sector/area of circle 110 degrees/360 degrees = 40 unit2/ pi r2 unit2 11/36 = 40/pi r2 11 pi r2 = 40 x 36 11 pi r2 = 1,440 r2 = 1,440/11 pi r = square root of 1,440/11 pi r = 20.3 unit approximately
