The right angle was divided into three angles, one of them measures 40º and the other two are unknown but equal.
To determine de measure on the other two angles you can use the angle addition postulate.
So the addition of the three angles is equal to 90º
[tex]\begin{gathered} 90=40+x+x \\ 90=40+2x \\ 90-40=2x \\ 50=2x \\ \frac{50}{2}=\frac{2x}{2} \\ 25=x \end{gathered}[/tex]
The measure of the other two angles is 25º
