Inscribed angle "V" and whose sides pass through points "A" and "B". Draw line "OA". Angle "BOA" is a central angle; call it "θ". Lines "OV" and "OA" are both radii of the circle, so they have equal lengths. Therefore, triangle "VOA" is isosceles, so angle "BVA" (the inscribed angle) and angle "VAO" are equal; let each of them be denoted as "ψ". Angles "BOA" and "AOV" are supplementary. They add up to 180°, since line "VB" passing through "O" is a straight line. Therefore, angle "AOV" measures 180° − "θ". It is known that the three angles of a triangle add
Back-in angle parking in traffic delays and considerable risk of collisions with pedestrians, bicyclists, and vehicles. Existing pull-in angle parking spaces can be converted to back-in angle parking by re-striping to flip the angle of the stall markings. Streets with parallel parking have also been converted to back-in angle parking. In either case, the pavement markings are often augmented with signage indicating that vehicles must be backed in. According to the Pedestrian & Bicycle Information Center, back-in angle parking provides motorists with better vision of pedestrians, bicyclists, motor vehicles, and other road users as they exit a parking space and enter moving traffic.