Answer:
The area of triangle is [tex]A=58.02\ ft^{2}[/tex]
Step-by-step explanation:
Let
B -----> the measure of the vertex angle of the isosceles triangle ABC
a and c -----> the two congruent sides of the isosceles triangle ABC
we know that
The area of a triangle applying the law of sines is equal to
[tex]A=\frac{1}{2}(a)(c)sin(B)[/tex]
we have
[tex]a=c=17.91\ ft[/tex]
[tex]B=21.21\°[/tex]
substitute in the formula
[tex]A=\frac{1}{2}(17.91)(17.91)sin(21.21\°)[/tex]
[tex]A=58.02\ ft^{2}[/tex]
