Question

help please!!
In the figure, if m∠ABD = 120º, then m∠ADC = ___
º.

Answer 1

@mathstudent55 @kodatfaulk @maemae16

Answer 2

Are you told more info, such as an angle is bisected?

Answer 3

did you see the image i attached?

Answer 4

Wait. I see it now.

Answer 5

Use the law of sines to find m<ADB.

Answer 6

i dont know it because my stupid online class doesnt teach it

Answer 7

@pooja195

Answer 8

What methods do you know for solving triangles?

Answer 9

Should you have learned the law of sines, but you were not taught?
If that's the case, I'll teach it to you now.

Answer 10

fine teach me please

Answer 11

Law of sines

Answer 12

Here is triangle ABC.
Each side has a small case letter to denote its lengthy.
Side a is opposite angle A.
Side b is opposite angle B.
Side c is opposite angle C.

So far this is just notation.
It's easy to remember which side is opposite each angle because each pair of opposite side and angle uses the same letter in capital and lower case forms.

Answer 13

Law of Sines

\(\dfrac{a}{\sin A} = \dfrac{b}{\sin B} = \dfrac{c}{\sin C}\)

Answer 14

The law of sines is the equation above.
In a triangle, the ratio of the length of a side to the sine of the opposite angle is the same for each side and its opposite angle.

Answer 15

If you can use two of those fractions, and you know 3 out of the 4 values, you can solve for the 4th value.

Answer 16

Let's look at your problem.

Answer 17

okay so D would also be 120?

Answer 18

We are now dealing only with triangle ABD.
Forget for now the rest of the figure.
In order to use the law of sines, we must have one of the three fractions fully known.
Look for a side and its opposite angle that are both known.

Answer 19

m<ABD is 120 deg. That is given.
We need to find m<BDA.

Answer 20

okay so how do we do that using that formula

Answer 21

I asked above.
Look at triangle ADB.
Do you see a side of the triangle and the opposite angle that are both known?