Divide the area by the value of Pi to get the diameter. Divide the diameter by 2 to get the radius !
Radius = 12.414 inches (to 3 dp)
Roughly 78
The arc is: 19.06 units
Area of circle of 132 inch diameter = 13684*78 sq inches = 10.56 sq yards.
Circumference of a circle = PI x D, so answer is 3.142 x 78 = 245.08 ft
Radius = 12.414 inches (to 3 dp)
Area = pi x radius x radius (pi = 3.14) Area = 3.14 x 5 x 5 Area = 78.5
78 cm2
Roughly 78
The arc is: 19.06 units
Length of arc = angle of arc (in radians) × radius of circle With a ratio of 7:8 the area of the sector is 7/8 the area of the whole circle. This is the same as saying that the circle has been divided up into 8 equal sectors and 7 have been shaded in. Dividing the circle up into 8 equal sectors will give each sector an angle of arc of 2π × 1/8 7 of these sectors will thus encompass an angle of arc of 2π × 1/8 × 7 = 2π × 7/8 = 7π/4 Thus the length of the arc of the sector is 7π/4 × radius of the circle. --------------------------------- Alternatively, it can be considered that as 7/8 of the area is in the sector, the length of the arc is 7/8 the circumference of the circle = 7/8 × 2π × radius = 7π/4 × radius.
Area covered by the wiper is that of a semi-circle with diameter D, or the length of the solar panel - 156 cm.So the area = (1/2)*(PI/4)*(D2) = (1/2)*(PI/4)*(156cm2) = 9556.72 cm2Now find the area of the solar panel: area = length*width = 156 cm * 78 cm = 12,168 cm2Now % area cleaned will be the area of the wiper / area of the panel:9556.72 cm2 / 12168 cm2 * 100% = 78.5%
The area of the plate is equal to pi times the square of the radius. Since the plate has a 10 inch diameter, the radius is 5 inches. Therefore, the area is equal to pi times 25, or about 78. 5 inches.
Area of circle of 132 inch diameter = 13684*78 sq inches = 10.56 sq yards.
Rigel has a radius of about 78 solar radii or 0.363 AU.
x2 + y2 - 2x - 18y = -78 x2 - 2x + 1 + y2 - 18y + 81 = 81 + 1 - 78 (x - 1)2 + (y - 9)2 = 4 (x - 1)2 + (y - 9)2 = 22 So the radius of the circle is 2, and it's center is located at the point (1, 9).
Circumference of a circle = PI x D, so answer is 3.142 x 78 = 245.08 ft