Isosceles triangle
ΔPQR:
∠R = ∠Q = (180° - 40°):2 = 70°
2x = 70°⇒ x = 35°
ΔSTV:
SV = TV
[tex]\tt 2x+6 = 3x-6\\\\3x-2x=6+6\\\\x=12[/tex]
