Question

I'd like to confirm my work's correct? Or, was I supposed to use one of the trigonometric functions to solve this? Help?

Answer 1

To find the area of triangle ABC

two side length and angle between them are given, then to find the area of the triangle.

we have that,

Area of the triangle is,

`A=(1)/(2)ab\sin \theta`

where a,b are the two sides of the triangle and theta is the angle between them.

Here, a=10, b=9, theta= 155 degree.

Substituting the values we get,

`=(1)/(2)(10)(9)\sin 155\degree`

we have that, sin 155 degree=0.42261

Using this, we get

`=(1)/(2)(90)(0.42261)`
`=(38.0356)/(2)`
`=19.0178`

Answer is: Area of triangle ABC is 19.0178 sq.cm.