Question

The diagonal of the rectangle abcd interscet at o. If angleCOD =78°, then angle OAB

Answer 1

Step-by-step explanation:

Since in a rec diagonal are equal and bisect each other

∴OD=OA

and  ∠S opp to equal sides are equal 

∴∠1=x

Now, In ΔODA

∠DOA=700 (vertically opp. ∠S)

x+∠1+70=1800 (∠ sum prop)

and ∠1=x

∴x+x+70=180

2x=110

x=2110

x=550

⇒∠ODA=550