How do I answer this Question? It’s phythagoras theorem!

Answer:
C = 11.18 D= 20
Step-by-step explanation:
Let's start with C
Square root both areas of the squares
[tex]\sqrt{25} =5[/tex]
[tex]\sqrt{100}=10[/tex]
Then use the Pythagoras Theorem: [tex]a^{2} +b^{2} =c^{2}[/tex]
[tex]10^{2} +5^{2} =125[/tex]
[tex]\sqrt{125} =11.18033989[/tex] = C
Moving on to D
Square root both areas of the squares
[tex]\sqrt{841} =29[/tex]
[tex]\sqrt{441} =21[/tex]
29 is the hypotenuse, we are trying to find the other leg, so:
[tex]29^{2} -21^{2} =400[/tex]
[tex]\sqrt{400} =20[/tex] = D