## Elementary Geometry for College Students (6th Edition)

Area = $\frac{1}{2}$* 5*6* sin78°
Using theorem 11.4.1 The area of the given triangle is = $\frac{1}{2}$ab sinγ Given a =5 b=6 and γ = 78° therefore Area = $\frac{1}{2}$* 5*6* sin78°