एक समचतुर्भुज ABCD के दोनों विकर्ण बिंदु O पर काटते है यदि ∠BDC = 60° हो तो ∠OAB = ? - - Ek SamChaturbhuj ABCD Ke Dono vikarn Bindu O Par Kaatate Hai Yadi ∠BDC = 60° Ho To ∠OAB = ? Maths in hindi, quadrilaterals 40° question answers in hindi pdf 30° questions in hindi, Know About 60° Maths online test Maths notes in hindi quiz book 50°