Answer:
The area of the shaded region is [tex]11.6\ cm^{2}[/tex]
Step-by-step explanation:
we know that
The area of the shaded region is equal to the area of the sector of circle of angle 68.9 degrees minus the area of the isosceles triangle
step 1
Find the area of sector of the circle
The area of circle is equal to
[tex]A=\pi r^{2}[/tex]
assume
[tex]\pi =3.14[/tex]
[tex]r=9.28\ cm[/tex]
substitute
[tex]A=(3.14)(9.28)^{2}[/tex]
[tex]A=270.41\ cm^{2}[/tex]
Remember that the area of a circle subtends a central angle of 360 degrees
so
using proportion Find out the area of a sector with a central angle of 68.90 degrees
Let
x -----> the area of a sector
[tex]270.41/360=x/68.90\\\\x=68.90*270.41/360\\\\x=51.75\ cm^{2}[/tex]
step 2
Find the area of the isosceles triangle
Applying the law of sines
The area is equal to
[tex]A=(1/2)r^{2}sin(68.90)[/tex]
we have
[tex]r=9.28\ cm[/tex]
substitute
[tex]A=(1/2)(9.28)^{2}sin(68.90)=40.17\ cm^{2}[/tex]
step 3
Find the area of the shaded region
[tex]51.75-40.17=11.58\ cm^{2}[/tex]
Round to the nearest tenth
[tex]11.58=11.6\ cm^{2}[/tex]