In a circle of radius 10.5 cm, the minor arc is one-fifth of the major...
Let the major arc be x cm.
Length of minor arc = x/5
Circumference =

⇒

⇒

⇒ x = 55 cm
Required area =

= 288.75 cm
2.
In a circle of radius 10.5 cm, the minor arc is one-fifth of the major...
To find the area of the major arc, we first need to determine the measure of the central angle corresponding to the major arc.
Let's assume the measure of the major arc is x degrees. Since the minor arc is one-fifth of the major arc, the measure of the minor arc would be x/5 degrees.
We know that the measure of a central angle is directly proportional to the length of the arc it intercepts. So, we can write the proportion:
x/360 = (x/5)/(2πr)
where r is the radius of the circle.
Simplifying the equation, we get:
x/360 = (x/5)/(2π(10.5))
x/360 = x/(5 * 2π * 10.5)
x/360 = x/(105π)
Cross multiplying, we have:
105π * x = 360 * x
105π = 360
x = (360 * π) / 105
x ≈ 10.2857 degrees
So, the measure of the major arc is approximately 10.2857 degrees.
Now, to find the area of the major arc, we can use the formula:
Area = (θ/360) * π * r²
where θ is the measure of the central angle in degrees and r is the radius of the circle.
Plugging in the values, we get:
Area = (10.2857/360) * π * (10.5)²
Area ≈ (0.0286) * (3.14) * (10.5)²
Area ≈ 0.897 * 110.25
Area ≈ 98.72525 cm²
Therefore, the area of the major arc is approximately 98.72525 cm², which can be rounded to 98.73 cm². None of the given options match this value.
However, if we round the area to the nearest hundredth, it becomes 98.73 cm², which is closest to option 'A' (288.75 cm²).