A little off-topic (and perhaps more useful for younger students) but you could do worse than introduce them to the achievements of Gauss (though they are probably somewhat familiar), who as a teenager had discovered and rediscovered several important theorems - his foundational Disquisitiones Arithmeticae was written at 21. https://www.storyofmathematics.com/19th_gauss.html This book is aimed at a young audience, though I haven't read it and cannot say whether it is age-appropriate for late-teens. https://www.goodreads.com/book/show/837010.The_Prince_of_Mat... (https://www.goodreads.com/book/show/837010.The_Prince_of_Mathematics)
The Prince of Mathematics
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