It is closer to 1.4
Explanation:
This is a 45 45 90 triangle
To find the hypotenuse of this triangle it is any side length times the square root of two.
Formula: Square Root = sqrt
Hypotenuse = SideLength*sqrt(2) ; 1*sqrt(2) = 1.412...
Rounded to the nearest tenths it is closer to 1.4 than 1.5