Given
Sides
13 mm, 18 mm, 14 mm
Using the Pythagorean theorem, compare the square of the longest side to the sum of the other two sides
[tex]\begin{gathered} a^2+b^2\text{ ? }c^2 \\ 13^2+14^2\text{ ? }18^2 \\ 169+196\text{ ? }324 \\ 365>324 \end{gathered}[/tex]Since the sum of the square of two sides is greater than the square of the longest side, the triangle is acute.
