Answer:
y = 2√5.
Explanation:
Consider the smallest triangle.
Applying Pythagoras theorem:
y^2 = x^2 + 2^2
The smallest and larger triangle (the one with one side = 8) are similar so we have the proportions :
x/2 = 8/x
---> x^2 = 16
---> x = 4.
Therefore , substituting for x in the first equation:
y^2 = 4^2 + 2^2
---> y^2 = 20
---> y = √20
---> y = 2√5.