Question

in given figure triangle odc triangle oabb triangle boc=125,odc70,then the value of triangle oab will be ​

Answer 1

In the given figure,

∠DOC = 180° - ∠COB [∵ ∠DOC and ∠COB from a linear pair]

∠DOC = 180° - 125°

∠DOC = 55°

In ΔODC,

∠DCO = 180° - (∠DOC + ∠ODC) [angle sum property of a triangle]

∠DCO = 180° - (55° + 70°)

∠DCO = 180° - 125°

∠DCO = 55°

In ΔODC and ΔOBA

ΔODC ∼ ΔOBA (given)

⇒ ∠DCO = ∠OAB

Thus, ∠OAB = 55°