Final answer:
The value of the radius of the arc is r. The answer is (d) 2√m.
Step-by-step explanation:
The value of the radius of the arc is r.
To understand why the radius of the arc is r, we can consider the definition of an arc.
An arc is a portion of the circumference of a circle. In this case, the barn roof is designed as an arc of a circle with a radius of r.
So, the answer to the question is (d) 2√m, as the value of the radius of the arc is 2√m.