The value of angle 1 in the triangle is 35°
Congruent triangles have exactly the same shape and size. Corresponding angles and sides are equal, making the triangles identical when superimposed.
The concept of congruence implies that all angles and sides of one triangle match those of another.
From the triangles
angle y = angle N= 90°
angle Z = 55
Therefore
angle 1 = 180-( 90+55)
= 180 - 145
= 35°
Therefore the measure of angle 1 is 35°