Given:
Consider the below figure attached with this question.
To find:
The per perimeter of the isosceles trapezoid. Round all figures to the nearest hundredths place.
Solution:
Consider the isosceles trapezoid is ABCD.
Draw two perpendicular from C and D to AB as shown in second figure.
Now, CDEF is a rectangle,
[tex]EF=CD=9\text{ ft}[/tex]
[tex]AB-EF=13-9[/tex]
[tex]AB-EF=4\text{ ft}[/tex]
It is an isosceles trapezoid, so [tex]\Delta ADE\cong \Delta BCF[/tex].
[tex]AE=BF=\dfrac{4}{2}=2\text{ ft}[/tex]
Now,
[tex]AE^2+DE^2=AD^2[/tex] [Pythagoras theorem]
[tex]2^2+4^2=AD^2[/tex]
[tex]4+16=AD^2[/tex]
[tex]\sqrt{20}=AD[/tex]
[tex]AD=BC\approx 30.94[/tex] [Isosceles trapezoid]
Find the perimeter of the figure.
[tex]Perimeter=AB+BC+CD+AD[/tex]
[tex]Perimeter=13+4.47+9+4.47[/tex]
[tex]Perimeter=30.94\text{ ft}[/tex]
Therefore, the correct option is c.
