TS EAMCET 11-Sep-2020 Shift 2 Solved Paper

Let a triangle ABC of sides a,b,c, having area Delta
Area =∆
‌

1

2

bc‌sin‌A=∆....(i)
and ‌‌‌

1

2

ac‌sin‌B=∆ ....(ii)
and ‌‌‌

1

2

ab‌sin‌c=∆....(iii)
Using cosine rule
a2=b2+c2−2bc‌cos‌A
and ‌‌b2=a2+c2−2ac‌cos‌B
and ‌‌c2=a2+b2−2ab‌cos‌C
On adding, we get
Now, from
Eq. (i) bc=‌

2∆

sin‌A

Eq. (ii), ac=‌

2∆

sin‌B

Eq. (iii), ‌‌ab=‌

2∆

sin‌C

Putting these values in Eq. (iv), we get