Respuesta :

Answer:

A

Step-by-step explanation:

The sum of the 3 angles in a triangle = 180°

Sum the 3 given angles and equate to 180

y + y - 12 + 56 = 180 ← simplify left side

2y + 44 = 180 ( subtract 44 from both sides )

2y = 136 ( divide both sides by 2 )

y = 68° → A

Hey there!

First, we know that all the angles sum to 180 degrees (just like all the angles in a square sum up to 360).

Second, what we will need to do is subtract the first number from 180. (As shown below):

180 - 56 = 124

As you can see above, our answer is 124.

Third, we have this equation:

' 124 + y - 12 = 180 '

As mentioned in the beginning, we need to find what y equals.  

Forth, we will solve the equation. (Shown below)

1 . Add 12 to both sides (cross out the double 12)

2. Bring down the 124 + y

3. Lastly, subtract 124 from 192. Your answer is 68.

124 + y - 12 = 180

↓        + 12   + 12

124 + y        = 192

192 - 124 = 68

Your answer is choice A. 68.

Hope this helps!