a.
\Arc(
) length of the circle is
, where
.
When
and
, the radius of the circle is
.
Consider
.
Substitue
and
in above equation.

\
Now the trigonometric equation is
, where
.
Let the functions are
and
.
Draw a coordinate plane.
\Graph the two functions
and
on the interval
in same window.
Graph :
\
Observe the above graph :
\The two functions intersects at
on the interval
.
Thus,
.
The value of
is
radians.
b.
\Find the angle
in radian measure.
Area of the shaded region is
.
Consider
.
Substitue
and
in above equation.

\
Now the trigonometric equation is
.
Let the functions are
and
.
Draw a coordinate plane.
\Graph the two functions
and
on the interval
in same window.
Graph :
\
Observe the above graph :
\The two functions intersects at
on the interval
.
When the area is 36 square inches and the radius is 5 inches, then the measure of
is
radians.
a. The value of
is
radians.
b. When the area is 36 square inches and the radius is 5 inches, then the measure of
is
radians.