Math, asked by sourabhbajaj, 1 year ago

prove that the sum of a pair of opposite angles of a quadrilateral is 180°

Answers

Answered by JAMES1111
4
Given : Let ABCD is cyclic quadrilateral.
To prove : ∠A + ∠C = 180°  and ∠B + ∠D = 180°.
Construction : join OB and OD.
Proof : ∠BOD = 2 ∠BAD
     ∠BAD = 1/2∠ BOD
Similarly ∠BCD = 1/2 ∠DOB
∠BAD + ∠BCD = 1/2∠BOD + 1/2 ∠DOB
                   =1/2(∠ BOD + ∠DOB)
                   = (1/2)X360° = 180°
Similarly ∠B + ∠D = 180°

sourabhbajaj: plz give diagram also
JAMES1111: YES I CAN'T DRAW IN THIS APPS TRYING ...,,,,
sourabhbajaj: draw on page and send pic
JAMES1111: north side A south west B south C south east D outer side circle inner quadltrl mid point O
JAMES1111: I think it helpsssss
sourabhbajaj: thnks
Similar questions