Answer:
28.32
Step-by-step explanation:
using the formula [tex]a^{2} +b^{2} =c^{2}[/tex], you get [tex]21^{2} +19^{2} =c^{2}[/tex].
then you get [tex]441+361=802[/tex]
your answer needs to be the square root of 802.
the square root of 802 is 28.319604517
Which rounded to the nearest tenths is 28.32