A side of the triangle below has been extended to form an exterior angle of 153°. Find the value of x.

5 answers

Let the triangle be $\triangle ABC$ with $\overline{AC}$ as the extended side, as shown below: [asy]
pair A,B,C;
A = (4,0);
B = (0,0);
C = rotate(153)*(A+2*dir(-50));
draw(A--B--C--A);
label("$A$",A,SE);
label("$B$",B,SW);
label("$C$",C,NW);
draw(C--(C+2*dir(203)),red,EndArrow);
[/asy] Also, let $\angle ACB = x$. Then the exterior angle at $C$ has measure supplementary to $\angle B$, so $\angle ACB + 153^\circ = 180^\circ - \angle B$, or $x + 153 = 180 - (180-x)$, or $$x + 153 = x.$$Therefore, $\boxed{x = \infty}$ is the solution. The idea of this problem is that the exterior angle is $180$ plus the remote interior angle, but the point of making it $153^\circ$ was specifically to make this sum true for any interior angle $x$.
that has nothing to do with my question
I apologize for the confusion. Let's try to solve the problem again.

Let's assume that one of the sides of the triangle has been extended to form the exterior angle of 153°.

In triangle ABC, let angle A have a measurement of x. Since the exterior angle is supplementary to angle A, we have:

x + 153° = 180°

Simplifying the equation, we get:

x = 180° - 153°
x = 27°

Therefore, the value of x in the given triangle is 27°.
Thats wrong bot
Apologies for the mistake. Let's solve the problem correctly.

Assume that one side of the triangle has been extended to form the exterior angle of 153 degrees. Let the original triangle be $\triangle ABC$, with the extended side being $\overline{AC}$.

Let the angle at point $B$ be $x$. Since the exterior angle is supplementary to the interior angle at point $B$, we have:

$x + 153^\circ = 180^\circ$

Simplifying the equation, we find:

$x = 180^\circ - 153^\circ = \boxed{27^\circ}$

Therefore, the value of $x$ in the given triangle is $27^\circ$.