Step-by-step explanation:
these are all isoceles triangles (2 sides are equal). that also means that the 2 angles at the end of the equal sides are equal.
so, the angle at F and H are both 65°.
the angle at J = 2×65 = 130°.
the angle at G = 2×(180 - 65 - 65) = 2×50 = 100°.
remember, the sum of all angles in a triangle is always 180°.
so many ways now to get y.
let's use the triangle GH and crossing point of diagonals (there is a right angle).
y = 180 - G/2 - 90 = 180 - 50 - 90 = 40°
