Question

5. In a triangle ABC, if (r, +r,) (r, +r)(r;+r,) =
4RK then K=
1)s 2 A 3 A 4) s²​

Answer 1

Answer:

$(r + r)(r + r)(r + r) = 4rk \\ (2r)(2r)(2r)(2r) = 4rk \\ 16 {r}^{4} = 4rk \\ \frac{16 {r}^{4} }{4} = rk \\ 4 {r}^{4} = rk \\ \frac{4 {r}^{4} }{r} = k \\ 4 {r}^{3} = k$