Question

for the parallelogram, if m∠2 = 3x - 28 and m∠ 4 = 2x - 12, find m∠3. The diagram is not drawn to scale.

Answer 1

a) 20
b) 16
c) 160
d) 170


I think it's a, but I could be wrong.

Answer 2

Well in a parallelogram, opposite angles are congruent.
So can you solve 3x-28=2x-12 for x?

Answer 3

I keep getting 40 -.-

Answer 4

Haha okay lemme show ya
3x-28=2x-12
To solve for x, you need to combine the like terms. So x's with x's and integers with integers. So I'm gonna subtract 2x from both sides first.
x-28=-12 Then add 28 to both sides.
x=16

So, to find the degrees of angles 2 & 3, you plug in 16 to either of the equation thingys.
measure of angle2 =3x-28
=3(16)-28
=48-28
=20

So we know that Angles 2 and 4 equal 20 degrees, right?

Answer 5

I knew I was forgetting something.

Answer 6

Adjacent angles (angles next to each other) are supplementary, meaning they add to equal 180 degrees.
So you can find the measure of angle 3 by subtracting 20 from 180. :)
Hope that helps!

Answer 7

It did help ^_^ thank you

Answer 8

No prob :)