Answer:
Explanation:
y = 5
All sides measure the same So 8y= 40 y = 5
x = 30 degrees
The straight line of 40+40 is a straigth angle of 180 Each angle of equilateral triangle is 60 degrees.So its supplementary is 120.The other 2 angles need to add to 60 (30 each) to sum 180 in a triangle