Sir in chapter 13 of 10 class in ex 13.4 of 3 question why the area of triangle added in solution

Sir in chapter 13 of 10 class in ex 13.4 of 3 question why the area of

1.	Sir in chapter 13 of 10 class in ex 13.4 of 3 question why the area of triangle added in solution
Answer» Koi abswer nahi