Question

If l||m and the measure of angle 7 is twice the measure of angle 2, then the measure of angle 7 is

30
60
90
120

Answer 1

Hi, Luka,

This is a case where it helps if you draw a picture.

Let me give you a similar problem, and I hope it is close to yours

Here is a line with another line going through it (I'll let you imagine the line going up and to the right, and down and to the left.

The large angle is twice the size of the small angle.

A B
__________________/__________

We know that angles A plus B must be equal to 180 degrees, so

A = 2B

A + B = 180

2B + B = 180

3B = 180
\
B = 60

The small angle is 60 degrees

What is the large angle's measure?

Is it twice the measurement of the small angle?

Do they add up to 180 degrees?

In your problem, the two parallel lines, with one line passing through both of them, also means that four of the angles have equal measures, and so do the other four angles.

I bet you can finish your problem from here.