document.write( "Question 305922: How many heptagons is it possible to construct by joining the vertices of a decagon? Is there a formula for this? It seems like there is a systematic way to figure this out, but I'm stuck. Thanks. \n" ); document.write( "
Algebra.Com's Answer #219134 by scott8148(6628)\"\" \"About 
You can put this solution on YOUR website!
how many ways can a group of seven be selected from ten things, order does NOT count\r
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\n" ); document.write( "\n" ); document.write( "10C7 = 120
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