Practicing Success
In the given figure AB = DB and AC = DC. If $\angle A B D=58^{\circ}$ and $\angle DBC=(2x-4)^{\circ}, \angle A C B=(y+15)^{\circ}$ and $\angle D C B=63^{\circ}$, then the value of 2x + 5y is : |
259 325 268 273 |
273 |
As AB = DB, AC = DC, and BC is common for two triangle So, \(\Delta \)ABC = \(\Delta \)DBC So, \(\angle\)ABC = \(\angle\)DBC = \(\angle\)ABD/2 ⇒ \(\frac{58}{2}\) = \({29}^\circ\) So, \({2x\; -\; 4 }^\circ\) = \({29}^\circ\) ⇒ 2x = \({33}^\circ\) Again, \(\angle\)ACB = \(\angle\)DCB = \({63}^\circ\) So, (y + \({15}^\circ\)) = \({63}^\circ\) ⇒ y = \({48}^\circ\) So, 2x + 5y = \({33}^\circ\) + 5 x \({48}^\circ\) ⇒ \({33}^\circ\) + \({240}^\circ\) ⇒ \({273}^\circ\) Therefore, the answer is \({273}^\circ\) |