find the length of the missing side of the right triangle.

Answer:
[tex] \boxed{ \bold{ \huge{ \boxed{ \sf{13 \: \: units \: }}}}}[/tex]
Step-by-step explanation:
Perpendicular ( p ) = 5
Base ( b ) = 12
Hypotenuse ( h ) = ?
Finding the length of missing side
Using Pythagoras theorem
[tex] \boxed{ \sf{ {h}^{2} = { p}^{2} + {b}^{2} }}[/tex]
plug the values
⇒[tex] \sf{ {h}^{2} = {5}^{2} + {12}^{2} }[/tex]
Evaluate the power
⇒[tex] \sf{ {h}^{2} = 25 + 144}[/tex]
Add the numbers : 25 and 144
⇒[tex] \sf{ {h}^{2} = 169}[/tex]
Squaring on both sides
⇒[tex] \sf{ \sqrt{ {h}^{2} } = \sqrt{169}} [/tex]
Calculate
⇒[tex] \sf{ {h} = 13 \: units}[/tex]
Hope I helped!
Best regards! :D