Angles between two chords

Project ID: 
6000000011
Accepted: 
SubArea: 
Type: 
Layout: 
Question: 
Clock faces are shown in the picture. Inside each clock face there are two chords drawn connecting the numbers on the clock face. Match the marked angles between the chords with their measures.
Question 1 Image: 
Answer 1: 
$45^\circ$
Question 2 Image: 
Answer 2: 
$60^\circ$
Question 3 Image: 
Answer 3: 
$75^\circ$
Question 4 Image: 
Answer 4: 
$120^\circ$
Question 5 Image: 
Answer 5: 

$135^\circ$

Question 6 Image: 
Answer 6: 
$90^\circ$
Tex: 
% http://math4u.vsb.cz/ticket/32003 \nonstopmode \documentclass[nofield,minipage]{m4u-sparuj} \input \jobname_\langfile_data.tex \newcommand\OBR[5][4mm]{ \obrMsr{-1.3,1.35,-1.3,1.35}[3.5cm,] { %\obrClip \footnotesize \obrKrizek {0,0}{below}{} \draw (0,0) circle (1); \foreach \i in {1,...,12} {\draw ({cos(90-(\i)*(360.0/12))},{sin(90-(\i)*(360.0/12))}) node {} coordinate (A\i);} \draw[name path = line 1] (A#2)--(A#3); \draw[name path = line 2] (A#5)--(A#4); \path[name intersections/.expanded = {of = line 1 and line 2, by = V}]; \obrUhelB*[#1] {A#3}{V}[?]{A#4} \foreach \i in {1,...,12} {\draw ($1.27*(A\i)$) node {\colorbox{white}{\!\!${\i}$\!\!}};} \foreach \i in {1,...,12} {\draw ($1.025*(A\i)$) -- ($0.975*(A\i)$);} } } \otazka{\OBR 7{11}18}{$45^\circ$} \otazka{\OBR 5137}{$60^\circ$} \otazka{\OBR 8{11}39}{$75^\circ$} \otazka{\OBR 614{11}}{$120^\circ$} \otazka{\OBR 6{11}4{10}}{$135^\circ$} \otazka{\OBR[3mm] 2{10}15}{$90^\circ$} \NastavOD{6} \begin{document} \TAJENKA \preQuestion \Question \vspace*{-10pt} \begin{minipage}{\linewidth} \preQuestions \QuestionsMulti[-10pt]{\textbf{\TEXTQ}}{\otazkysloupce} \vspace*{-20pt} \preAnswers \AnswersMulti[\odpovedimezera]{\textbf{\TEXTA}}{\odpovedisloupce} \postAnswers \end{minipage} \vspace*{-6cm} \end{document}