यदि tan 2A = cot (A - 21°) हो तो 2A एक न्यून कोण हो तो A = ? - - Yadi tan 2A = cot (A - 21°) Ho To 2A Ek Nyun Kon Ho To A = ? Maths in hindi, trigonometry 69° question answers in hindi pdf 21° questions in hindi, Know About 37° Maths online test Maths notes in hindi quiz book Inme Se Koi नही