## Understand the problem

##### Source of the problem

##### Topic

##### Difficulty Level

5 out of 10

##### Suggested Book

## Start with hints

Do you really need a hint? Try it first!

Draw a clear image of the given problem

translate ABCD along the vector AD SO A’ and D are the same , and so that B’ and C are the same

now , \(\angle COD +\angle CO’D=\angle COD+\angle A’O’D’ =180 \)

so OCO’D is cyclic . therefore \(\angle OO’C =\angle ODC\)

Also , vector BC and OO’ both equal AD so OBCO’ is parallelogram . therefore

\(\angle OBC =\angle OO’C=\angle ODC \)

## Connected Program at Cheenta

# I.S.I. & C.M.I. Entrance Program

Indian Statistical Institute and Chennai Mathematical Institute offer challenging bachelor’s program for gifted students. These courses are B.Stat and B.Math program in I.S.I., B.Sc. Math in C.M.I.

The entrances to these programs are far more challenging than usual engineering entrances. Cheenta offers an intense, problem-driven program for these two entrances.

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