Answer:
No, it does not follow the Pythagorean Theorem.
Explanation:
A right triangle must follow the equation a^2 + b^2 = c^2 for its sides to be true. 20^2 + 40^2 = 2000.
the square root of 2000 equals about 44.7213595.
Thus, a triangle with sides 20, 40, and 80 is not a right triangle.