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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def segment_area(seg):
    '''Compute the surface area of a segment.

    Approximated as a conical frustum. Does not include the surface area
    of the bounding circles.
    '''
    r0 = seg[0][COLS.R]
    r1 = seg[1][COLS.R]
    h2 = point_dist2(seg[0], seg[1])
    return math.pi * (r0 + r1) * math.sqrt((r0 - r1) ** 2 + h2)