In triangle $ABC$, the angles $\angle A$, $\angle B$, $\angle C$ form an arithmetic sequence. If $\angle A = 45^\circ$, then what is $\angle C$, in degrees?
The angles form an arithmetic sequence with common difference $\Delta$. [asy] pair A,B,C; A = (0,0); B = (2.25,0); C = (1,1.7); draw(A--B--C--cycle); draw(rightanglemark(B,A,C,2)); label("$A$",A,SW); label("$B$",B,SE); label("$C$",C,N); [/asy] Since the sum of the measures of the angles in a triangle is $180^\circ$, we have ∠A+∠B+∠C=180∘.