The side of the square is equal to the diameter of the circle, in this case 2a so the perimeter is 8a cm.
4.
You don't get circles that shape...
It is a 90 degree turn or circumference/4
Normally, the amount of the side of the rectangle below the quarter circle on it would expected to be calculated. However, the radius of the circle equals the amount that is subtracted, but in calculating the perimeter it has to be added back in again as it forms part of the perimeter. Thus the perimeter is the perimeter of the rectangle plus a quarter of the circumference of the circle. → perimeter = 2 × (20cm + 2 cm) + ¼ × 2 × π × 11 cm ≈ 44 cm + 3.14 × 11/2 = 61.27 cm.
The arc is one quarter of a circle so is 2pir, the other components of the quarter circle are the two radii, so perimeter is 2r+2pir = 2r(1+pi)
Eccentric circles.
The side of the square is equal to the diameter of the circle, in this case 2a so the perimeter is 8a cm.
4.
I believe 270 because a circle's perimeter is 360 so if you divide it by 0.75, you get 270.
You don't get circles that shape...
It is a 90 degree turn or circumference/4
You get 2 circles of diameter. If you were trying to find a perimeter, Never double the diameter. If you have a radius, You have to double it to get a perimeter.
No. You can only define a circle by radius, diameter, area, perimeter. Concentric circles have the same centre, therefore, if they were the same circles with the same radius, then they would all lie on top of each other and be effectively one circle.
Circumference is a special name for a circles perimeter. I think the answer you are looking for is radious.
Normally, the amount of the side of the rectangle below the quarter circle on it would expected to be calculated. However, the radius of the circle equals the amount that is subtracted, but in calculating the perimeter it has to be added back in again as it forms part of the perimeter. Thus the perimeter is the perimeter of the rectangle plus a quarter of the circumference of the circle. → perimeter = 2 × (20cm + 2 cm) + ¼ × 2 × π × 11 cm ≈ 44 cm + 3.14 × 11/2 = 61.27 cm.
The circumference of a circle with a diameter of 30 centimeters is: about 94.25 cm. You can easily do this calculation for other circles by multiplying the diameter by Pi (about 3.1416).