Angles.Triangles and polygons,

4.
x = ∠EHD (alt.∠s, AB//CD)
x = 86°


5.
y + ∠EHD = 180° (int.∠s,AB//CD)
y = 94°


6.
z = ∠EHD (corr.∠s, AB//CD)
z = 86°


7.
The sum of all interior angles of a pentagon
= (5 - 2) x 180° (5 sides in a polygon)
= 540°