Answer
$80^{\circ};\,40^{\circ};\,60^{\circ}$
Work Step by Step
Sum of the measures of angles in a triangle is $180^{\circ}$
$\implies (5x+5)^{\circ}+(4x-20)^{\circ}+(4x)^{\circ}=180^{\circ}$
$\implies (13x-15)^{\circ}=180^{\circ}$
$\implies (13x)^{\circ}=195^{\circ}$ or $x=\frac{195}{13}=15$
The angle measures are $(5x+5)^{\circ}=(5\times15+5)^{\circ}=80^{\circ}$,
$(4x-20)^{\circ}=(4\times15-20)^{\circ}=40^{\circ}$ and $(4x)^{\circ}=(4\times15)^{\circ}=60^{\circ}$.
