We have a rectangle and we must find m(∠1) and m(∠3).
1. We must use that the interior angles of a rectanhgle measure 90°, then
[tex]\begin{gathered} 60^{\circ}+m(\angle1)=90^{\circ} \\ \\ \end{gathered}[/tex]
Then, we must solve the equation for m(∠1)
[tex]\begin{gathered} m(\angle1)=90^{\circ}-60^{\circ} \\ m(\angle1)=30^{\circ} \end{gathered}[/tex]
2. We must use that ∠1 and ∠3 are alternate interior angles, so they measure the same
[tex]\begin{gathered} m(\angle1)=m(\angle3) \\ \text{ Knowing that }m(\angle1)=30^{\circ} \\ m(\angle3)=30^{\circ} \end{gathered}[/tex]
ANSWER:
m(∠1) = 30°
m(∠3) = 30°
