Question

And isosceles triangle has a bird types angle of 21. 21°. The two sides of the triangle reach 17.91 feet long. Find the area of a triangle.

Answer 1

17.91*21=376.11

i used one side of the triangle because both sides are equal

Answer 2

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

              $=\frac{ab\times \sin C}{2}\\\\=\frac{17.91 \times 17.91\times \sin137^{\circ}.18' }{2}\\\\=\frac{320.7681 \times 0.68}{2}\\\\=\frac{218.122308}{2}\\\\=109.061154$

=109.062 Square feet(Approx)