let the kite is the quadrilateral ABCD with the two pairs of adjacent congruent sides. (the diagram is also attached)
Now, its given in question, see from figure,
AB is congruent to AD
BC is congruent to DC
Now, let us join the points A & C to form AC ; and points B and D to form BD.
So, AC is common side to triangles ABC and ADC.
So, Because AB ≈AD
BC ≈ DC
And, AC is common, therefore,
triangle ABC is congruent to triangle ADC
⇒∠ ABC ≈ ∠ADC (These are the angles between the non-congruent sides)
