From the markings and lines, we can tell this is an equilateral triangle. Since it is an equilateral triangle, we know that each angle is 60°.
Using this information, we can make and solve an equation:
8y - 4 = 60° (we know that it is equal to 60°, since it is an equilateral triangle)
8y = 64° (we added both sides by 4 to get the y's alone on one side)
y = 8° (we divide both sides by 8 to find out what just y is)
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Answer:
So y is equal to 8°