Question

D. 18.3 Geometry math question no Guessing and Please show work

Answer 1

Pythagoras theorem
${a}^{2} = {b}^{2} + {c}^{2}$
In your case
${c}^{2} = {9}^{2} + {10}^{2}$
Which is
$\sqrt{c}$
Approximated result 13.45