Answer:
[tex]y=5[/tex]
Step-by-step explanation:
This is an isosceles triangle. The peculiarity of isosceles triangles is that two of their sides have an identical length, also angles opposite sides that are the same length are also the same. This means that these triangles not only have two equal sides, but also two equal angles. Therefore:
[tex]75=3x[/tex]
Solving for x:
[tex]x=\frac{75}{3} =25[/tex]
Hence:
[tex]\angle C =3x=3(25)=75[/tex]
Also, keep in mind that the sum of the interior angles of a triangle is equal to 180°, therefore:
[tex]75+75+4y+10=180[/tex]
Solving for y:
[tex]4y=180-75-75-10=20\\\\y=\frac{20}{4} =5[/tex]
