Answer:
A. 54°
Step-by-step explanation:
The sum of a standard (no curved lines) triangle's internal angles will always be 180°. You know the following:
1. The internal angles sum to 180°
2. One of the angles measures 72°
3. The remaining angles have the same unknown value, y
From this, you can write the following equation:
[tex]180 = 72 + 2y[/tex]
Then, to solve, first isolate y:
[tex]180 - 72 = 2y[/tex]
[tex]108 = 2y[/tex]
Then, simply divide by 2 to solve for y:
[tex]\frac{108}{2} = \frac{2y}{2} [/tex]
[tex]54 = y[/tex]
So, based on the information given, y=54°.
