Answer:
Step-by-step explanation:
Call high street is a, using  Pythagorean Theorem we have:
x^2 = 4 + a^2
b^2 = a^2 + 36
64 = x^2 + b^2
so we have x^2 = 16, a^2 = 12, b^2 = 48
so x= 4