Help please please help and try to explain so I get it and absorb the info

Answer:
[tex]20 { }^{2} + 21 {}^{2} = 29 {}^{2} [/tex]
Step-by-step explanation:
[tex]according \: to \: pythagoras \: thorem \: \\ 20 {}^{2} + 21 {}^{2} = 29 {}^{2} [/tex]
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