Remember that there are always 360 degrees in a full circle. Since [tex] m\angle1 = 90^{\circ} [/tex] (it is a right angle), we can find:
[tex] m\angle2 + m\angle3 = 270^{\circ} [/tex]
Substituting in the values provided in the problem into our equation gives us:
[tex] (x - 7) + 2x = 270 [/tex]
[tex] 3x - 7 = 270 [/tex]
[tex] x = \dfrac{277}{3} [/tex]
Given this, we can find the [tex] m\angle3 [/tex]:
[tex] m\angle3 = 2\Bigg( \dfrac{277}{3} \Bigg) ^{\circ}[/tex]
[tex] m\angle3 = \boxed{\dfrac{554}{3}^{\circ} \approx 184.67^{\circ}} [/tex]
