Answer:
See Explanation
Step-by-step explanation:
[tex] \because \angle 1 [/tex] and [tex] \angle 2 [/tex] are complementary.
[tex] \therefore m\angle 1+m\angle 2=90\degree... (1)[/tex]
[tex] \because \angle 2 [/tex] and [tex] \angle 3 [/tex] are complementary.
[tex] \therefore m\angle 2+m\angle 3=90\degree... (2)[/tex]
From equations (1) & (2), we find:
[tex] m\angle 1+m\angle 2=m\angle 2+m\angle 3
[/tex]
[tex] m\angle 1+m\angle 2-m\angle 2=m\angle 3
[/tex]
[tex] m\angle 1=m\angle 3[/tex]
Thus proved.