Answer:
8 = x
Step-by-step explanation:
all three sides are equal, so it is an equilateral triangle
if it is an equilateral triangle, each angle is 180/3 = 60 degrees
therefore
60 = 7x+4
subtract 4 from each side
60-4 = 7x+4-4
56 = 7x
divide by 7 on each side
56/7 = 7x/7
8 = x
