+1839 In triangle $ABC$, $\angle ABC = 90^\circ$, and $D$ is on side $\overline{BC}$ such that $\overline{AD}$ bisects $\angle BAC$. If $AB = 4,$ $BC = 3$, and $AC = 5,$ then find the area of $\triangle ADC$. Round your answer to the nearest integer.
+1926 Let's set some variables to solve this question.
Now, since AD bisects BAC
Let's let BD = 3 - x
Let's let CD = x
Now, we have the formula
\( BD / AB = CD / AC \\ (3 - x) / 4 = x / 5\\ 5 (3 - x) = 4x \\ 15 - 5x = 4x \\ 15 = 9x \\ x = 15/9 = 5/3 = CD\)
Thus, we finally can caclulate ADC as
\([ ADC ] = (1/2) (CD) ( AB) = (1/2) ( 5/3) ( 4) = 10 / 3 \)
Thus, The answer is \(10/3\)
Thanks! :)
