A5. How large is the largest interior angle of triangle $ABC$ (see figure)?
(A) $44^{\circ}$
(B) $89^{\circ}$
(C) $90^{\circ}$
(D) $176^{\circ}$
(E) It is impossible to determine.

![](https://cdn.mathpix.com/cropped/2024_06_07_474093644c4c736111d0g-2.jpg?height=297&width=492&top_left_y=1553&top_left_x=1413)
A5. Since the sum of the interior angles of a triangle is $180^{\circ}$, we can write the equation $x+\left(x+3^{\circ}\right)+$ $\left(2 x+1^{\circ}\right)=180^{\circ}$. The solution to the equation is $x=44^{\circ}$. The largest angle is $2 x+1^{\circ}=89^{\circ}$.