When the diameter of the circle is 50, S=3. 14X 50= 157.
Compasses are usually used to draw circles. The diameter and radius length of the inner circle of the same circle are always the same, and the circle has countless radii and diameters. A circle is a figure with axial symmetry and central symmetry. The axis of symmetry is the straight line where the diameter lies.
The length of a circle is the circumference of a circle. Two circles that can overlap are called equal circles, and there are countless symmetry axes. A circle is a regular n polygon (n is an infinite positive integer), and its side length is infinitely close to 0 but can never be equal to 0.
Extended data:
Sector arc length L= central angle (radian system) ×R= nπR/ 180(θ is central angle) (r is sector radius).
Sector area S=nπ R? /360=LR/2(L is the arc length of the sector)
Radius of cone bottom surface r=nR/360(r is the radius of bottom surface) (N is the central angle)
The positional relationship between a straight line and a circle:
1, straight lines and circles have nothing in common, which is called separation. AB is separated from circle O, d>r.
2. A straight line and a circle have two common points, which are called intersections. This straight line is called the secant of a circle. AB intersects with o and d
A straight line and a circle have only one common point, which is called tangency. This straight line is called the tangent of the circle, and the only thing in common is called the tangent point. The line between the center of the circle and the tangent point is perpendicular to the tangent line. AB is tangent to ⊙O, and d = r. (d is the distance from the center of the circle to the straight line)