Respuesta :

Answer:

c = 35

Step-by-step explanation:

[tex]c^{2} = a^{2} + b^{2}[/tex]

[tex]c^{2} = 21^{2} + 28^{2}[/tex]

[tex]c^{2} = 1225[/tex]

[tex]\sqrt{c^{2} } = \sqrt{1225}[/tex]

[tex]c = 35[/tex]