Respuesta :
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)
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)

Answer:
∠ABD = ∠ACD
Step-by-step explanation:
Given : ABCD is a quadrilateral
AB≈AC
DB≈DC
To Prove : ∠ABD = ∠ACD
Proof : We know that AB≈AC and DB≈DC
Draw a line join A and D (refer attached figure)
This divides quadrilateral into two triangles named as ΔABD and ΔACD
Now , We know that
AB≈AC (given) this means AB = AC
DB≈DC(given) this means DB=DC
AD=AD(common)
So , by SSS property of congruency ΔABD and ΔACD are congruent .
( SSS property is when all three sides in one triangle are the same length as the corresponding sides in the other)
Hence, ΔABD ≅ ΔACD
Since ΔABD ≅ ΔACD (Proved above)
⇒∠ABD = ∠ACD
Thus , Two angles between non-congruent sides are congruent.
