Answer
Area = =$\frac{1}{2}$*5*7*sin56°
Work Step by Step
Given,
a=5, b=7, α = 36° , β =88°
As we know the sum of all the angles of the triangle is 180°
in triangle ABC, α + β + γ = 180°
36° + 88° + γ = 180°
γ = 180° - 36° - 88°
γ =56°
By theorem 11.4.1
Area of triangle = $\frac{1}{2}$a*b*sinγ
=$\frac{1}{2}$*5*7*sin56°
