The area of a sector of a circle with a central angle of radians is . Find the radius of the circle. Do not round any intermedia
te computations. Round your answer to the nearest tenth.
1 answer:
Answer:
<h3>3.5ft</h3>Step-by-step explanation:
The question is incomplete. Here is the complete question.
Find the complete question in the diagram attached.
Area of a sector = θ/360 * πr² where;
r is the radius
θ is the angle substended by the sector
Given parameters
Area of the sector = 9ft²
central angle θ = 1.5 radians
Since 1 radians = 57.2958°
1.5 radians = (1.5 * 57.2958)
1.5 rad = 85.9437°
Substituting the given values into the formula;
Area of a sector = θ/360 * πr²
9 = 85.9437/360 * (3.14)r²
9 = 0.2387325 * 3.14r²
9 = 0.74962005r²
r² = 9/0.74962005
r² = 12.00608
r = √12.00608
r = 3.4641
r = 3.5 ft (to the nearest tenth)
Hence the radius of the circle is 3.5ft
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We know the height of the ladder (10 feet) and also the height off the ground of the windowsill (8.5 feet). That second side is opposite the angle a. So, when we consider angle a we know the length of the side opposite and of the hypotenuse.
Recall the sin of an angle can be found by using (opposite/hypotenuse).
So we have: sin a = 8.5 / 10. That is, sin a = .85
We are looking for the angle whose sin is .85 and can find this using the inverse sin function.
a is approximately 58.211669 degrees which is less than the 65 degrees and so safe.
Just to be on the safe side, I remind you that your calculator must be in degrees (not radians) to do this problem.