1) Given that the length of an arc is (1 / 3) π and the center angle of the opposite circle is 30 °, the radius of this arc is? 2) the arc length of a circle with radius 5 is exactly the same 1) Given that the length of an arc is (1 / 3) π and the center angle of the opposite circle is 30 °, then the radius of the arc is? 2) If the arc length of a circle with radius 5 is exactly equal to the circumference of a circle with radius 2, then in a circle with radius 5, the angle of the center of the circle opposite to the arc is () degrees

1) Given that the length of an arc is (1 / 3) π and the center angle of the opposite circle is 30 °, the radius of this arc is? 2) the arc length of a circle with radius 5 is exactly the same 1) Given that the length of an arc is (1 / 3) π and the center angle of the opposite circle is 30 °, then the radius of the arc is? 2) If the arc length of a circle with radius 5 is exactly equal to the circumference of a circle with radius 2, then in a circle with radius 5, the angle of the center of the circle opposite to the arc is () degrees

(1) Let R be the radius
(30 · π R) / 180 = (1 / 3) π ["·" denotes multiplication sign]
∴r=2
The radius is 2;
(2) Let its center angle be y degree
（y·π·5）/180 =2π·2
∴ y=144
That is, its center angle is 144 degrees
I'm glad to solve the above problems for you. I hope it will be helpful to your study

There is a curve which is arc-shaped, the length of the curve is 12M, and the center angle of the curve is 81 degrees. Find the radius r of the curve
Do you have anything more detailed

81/360*2*3.14*R=12
R is about 8.5

If the radius of an arc is 12 and the arc length is 4 π, then the center angle of the arc is ()
A. 60°B. 90°C. 120°D. 150°

According to the arc length formula: 4 π = n π × 12180, the solution is n = 60