Answer:
36
Step-by-step explanation:
I just have a feeling
Using Pythagorean theorem
[tex]\\ \sf\longmapsto b^2=51^2-24^2[/tex]
[tex]\\ \sf\longmapsto b^2=2601-576[/tex]
[tex]\\ \sf\longmapsto b^2=2025[/tex]
[tex]\\ \sf\longmapsto b=45[/tex]
