A map with a scale of 1 : 50,000 shows the locations of four towns A, B, C, and D.
The distance between Town A and Town B is 6 centimeters, the distance between
Town B and Town C is 7 centimeters, and the distance between Town C and Town D
is 8 centimeters. Given that m2ABC = m_ADC = 90°, find the actual distance
between Town A and Town D.