Answer: m∠1 = 128°, m∠2 = 26° and m∠3 = 26°.
Step-by-step explanation: We are given to find the measures of ∠1, ∠2 and ∠3 in the figure.
As shown in the attached figure, ABCD is a rhombus, where m∠A = 128°.
We know that, in a rhombus, all the sides are congruent, the opposite angles are congruent and the adjacent angles are supplementary.
So, from rhombus ABCD, we have
[tex]m\angle A=m\angle C~~~~~\textup{[opposite angles]}\\\\\Rightarrow m\angle 1=128^\circ.[/tex]
Also, in ΔBCD, we have
[tex]BC=CD~~\textup{[all the sides are congruent]}\\\\\Rightarrow m\angle 3=m\angle 2~~\textup{[angles opposite to congruent sides care congruent]}.[/tex]
Now, since the sum of three angles of a triangle is 180°, we have from ΔBCD that
[tex]m\angle 1+m\angle 2+m\angle 3=180^\circ\\\\\Rightarrow 128^\circ+m\angle 2+m\angle 2=180^\circ\\\\\Rightarrow 2\times m\angle 2=180^\circ-128^\circ\\\\\Rightarrow 2\times m\angle 2=52^\circ\\\\\Rightarrow m\angle 2=26^\circ.[/tex]
Therefore, m∠3 = 26°.
Thus, m∠1 = 128°, m∠2 = 26° and m∠3 = 26°.
