only part B and C . please help.

Answer:
Step-by-step explanation:
To determine if the given values are part of a right-angled triangle, we need to use the Pythagorean theorem, removing one of the variables, and if it results in the neglected value, it is a right-angled triangle.
[tex]a^2+b^2=c^2\\[/tex]
b.
[tex]21^2+24^2=c^2\\c=31.9[/tex]
DEF is not a right triangle.
c.
[tex]7.1^2+2.4^2=c^2\\c=7.5[/tex]
GHI is a right triangle.
Hope this helped! If you need more help with the practice, please comment below. Have a good day!