Question

If BC = 8.3, CD = 6.7, and AD = 11.6, find AB to the nearest tenth.

Answer 1

$|BC|=8.3;\ |CD|=6.7;\ |AD|=11.6\\\\|AC|^2+|CD|^2=|AD|^2\\\\|AC|^2+6.7^2=11.6^2\\\\|AC|^2=134.56-44.89\\\\|AC|^2=89.67\\---------------\\|AB|^2=|BC|^2+|AC|^2\\\\|AB|^2=8.3^2+89.67\\\\|AB|^2=68.89+89.67\\\\|AB|^2=158.56\\\\|AB|=\sqrt{158.56}\\\\|AB|\approx12.6$