### Triangles | Chapter 6 Exercise 6.5 Question 8:

In the following figure, O is a point in the interior of a triangle ABC, OD ⊥ BC, OE ⊥ AC and OF ⊥ AB. Show that

(i) OA^{2 }+ OB^{2} + OC^{2} − OD^{2} − OE^{2} − OF^{2} = AF^{2 }+ BD^{2} + CE^{2}

(ii) AF^{2} + BD^{2 }+ CE^{2} = AE^{2} + CD^{2} + BF^{2}

**Solution:** Detailed explanation of exercise 6.5 question 8 is given in the below image and YouTube video.