All sides are the same, hence, all three angles are the same, and each one of them is 60 degrees. Due to that:
7x + 4 = 60
7x = 56
x = 56/7 = 8
8y + 12 = 60
8y = 48
y = 48/8 = 6
Given the equation;

To solve, let us multiply through by the least common multiple of the the denominator of the three fractions wich is 24;
When two parallel lines are cut by a transversal, due to the natures of the different relationships among the angles, all of them will be either equal to the measure of the first angle or equal to that angle subtracted from 180. If the transversal is perpendicular to the parallel lines, forms a right angle, then both the angle given and the angle subtracted from 180 will be 90. This means all of the angles will be 90.
Answer:
B
Step-by-step explanation: