Question

an exterior angle of 108 degrees and the interior opposite anglea are in the ratio 4:5.find the angles of the triangles.

Answer 1

let the ratio be 4x and 5x
4x+5x=108°
9x=108°
x=108/90
x=18
4*18=72°
5*18=90°

Answer 2

Solution:                                                                                                               Let the interior opposite angle of the triangle be $4x$ and $5x$

$4x+5x=108^{0}$

$9x=108^{0}$

$x= \frac{108}{90}$

$x=18$

                                       

                        $4x=$4x18=$72^{0}$

                        $5x=$5x18=$90^{0}$