The correct answer is B) 9 m.
The measure of the sector of circle R is 32π/9 m. The measure of the central angle is 80°. This means that the sector is 80/360 = 2/9 of the circle. The area of a circle is given by A=πr², so the area of the sector is A=2/9πr². To verify this, 2/9π(4²) = 2/9π(16) = 32π/9.
Using this same formula for circle S, we will work backward to find the radius:
18π = 2/9πr²
Multiply both sides by 9:
18*9π = 2πr²
162π = 2πr²
Divide both sides by 2π:
162π/2π = 2πr²/2π
81 = r²
Take the square root of both sides:
√81 = √r²
9 = r
In this question, the speed of the dolphin is already given, but the unit is different. The speed of the dolphin is given as 40 miles per hour and it has to be converted to feet per hour.
We already know that 1 mile = 5280 feet
Then
40 mile = 5280 * 40 feet
= 211200 feet
So the speed in feet per hour will be 211200 feet per hour. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar problems without requiring any help from outside.
I think that is the right answer
The answer to this question is H. I hoped I helped you.
