Question

In the diagram m∠3 = x + 30 and m∠4 = 2x - 80. What is the measure of angle 3?
50
80
110
140

Answer 1

https://ivep.owschools.com/media/g_geo_ccss_2016/3/page28a.gif

Answer 2

Angle 3 and angle 4 are `vertical angles`

https://www.mathsisfun.com/geometry/vertical-angles.html

so this means that they are congruent angles. In other words,

m < 3 = m < 4

x+30 = 2x - 80

solve for x

Answer 3

Once you know what x is, replace x with that number in x+30 to find the final answer.