Answer with explanation:
Two equal angles of Isosceles Triangle =21.21°
Two equal sides of Isosceles Triangle =17.91 feet
Third Angle of Triangle
Using Angle sum property of triangle⇒Which states that sum of three angles of triangle is 180°.
→21°.21'+21°.21'+Third Angle=180°
→42°.42'+Third Angle=180°
→Third Angle=180°-42°.42'
→Third Angle=137°.18'
⇒Area of triangle

=109.062 Square feet(Approx)