I need help please this is hard and im to tired to do it

Answer:
CD = 5
Step-by-step explanation:
Using the distance formula
d = [tex]\sqrt{(x_{2}-x_{1})^2+(y_{2}-y_{1})^2 }[/tex]
with (x₁, y₁ ) = C (4, 7 ) and (x₂, y₂ ) = D (7, 11 )
CD = [tex]\sqrt{(7-4)^2+(11-7)^2}[/tex]
= [tex]\sqrt{3^2+4^2}[/tex]
= [tex]\sqrt{9+16}[/tex]
= [tex]\sqrt{25}[/tex]
= 5