Answer:
55.6 inch
Explanation:
the cardboard tree, the horizontal base and the diagonal would form a right angled triangle.
the carboard tree would be the height
the horizontal base would be the base
the diagonal would be the hypotenuse
the length of the diagonal base can be determined using the Pythagoras theorem
the Pythagoras theorem : a² + b² = c²
a = base
b = height
c = hypotenuse
48² + 28² = 3088
c = √3088 = 55.6 inch