Explanation:
The green triangle :
The angle x is 65°
this is because both the sides are equal so when the other angle is 65° angle x is also 65°
The blue triangle :
The angle x is 25°
this is because both the sides are equal so when the other angle is 25° angle x is also 25°
The red triangle :
The angle x is 45°
this is because both the sides are equal so when the other angle is 45° angle x is also 45°