App description

The following is the relationship between the relevant angles and edges:

• Angle ACE = angle ECD = 1⁄2 angle ACD

• Angle ACO = 90o - 1⁄2 angle BAC

• Angle OCE = angle ACE - ACO

• OE = 1⁄2 line BC x tan (OCE)

• AE = OA + OE

• ED = AD -AE

• Line EDF = 1⁄2 line BDC

• EF = sin (EDF) x ED