CAYLEY 2010 Problem 18

Past Contests CAYLEY CAYLEY - 2010
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1

In the diagram, R is the point of intersection of PT and QS,PQ=PR, and RS=RT. If \angle{PQR}=2x^\circ, then the measure of \angle{RST}, in degrees, is

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Answer Choices
A. 45-x
B. 90+\frac12x
C. 90-\frac12x
D. 45+2x
E. 90-x