Answer: [tex]30^{\circ}[/tex]
Step-by-step explanation:
In the given picture , we have two triangles ( one on another ) ,such that one triangle is inverted and share a common vertex. .
Then , the third angles of the lower triangle must be x [∵ Vertical angles are congruent.]
When we consider the lower triangle, we have
[tex]x+75^{\circ}+75^{\circ}=180^{\circ}[/tex] [ By Angle sum property ]
[tex]\Rightarrow\ x+150^{\circ}=180^{\circ}\\\\\Rightarrow\ x=180^{\circ}-150^{\circ}=30^{\circ}[/tex]
Hence, the measure of angle marked as x = [tex]30^{\circ}[/tex]