1. mathslover

2. Denebel

Is the 15 the length from BC?

3. mathslover

Ok so this is an easy question but my problem is that :how do I find the area of triangle AOD

4. mathslover

Yes denebel

5. hartnn

AOD isn't a triangle ....is it? u meant ACD?

6. mathslover

OH i meant triangle OBD

7. hartnn

isn't BO perpendicular to AD ?

8. mathslover

NOTE : I have solution but the answer given by the soln is totally wrong acc. to me I know that hartnn but... the soln does not go through that step

9. mathslover

it only goes find area of triangle AOB and then area of triangle ABC and then subtraction as u know

10. mathslover

Is that right step?

11. hartnn

u mean Area of ABC-ABD ?

12. mathslover

ar of ABC - ar ABO

13. mathslover

that is mentioned by : the book and i think where does BOD go ..

14. hartnn

thats not correct to find area ADC it must be ABC-ABD=ABC-ABO-BOD

15. mathslover

yes very right ... but the book was 'reliable' so I thought it may contain some trick so either figure is wrong or the soln right?

16. hartnn

yup, either of the two is incorrect.

17. mathslover

ok thankss