#### Answer

29

#### Work Step by Step

$21^2+20^2=x^2$
$441+400=x^2$
$841=x^{2}$
$\sqrt {841}=x$
$29=x$, because $29\times29=841$

Published by
Pearson

ISBN 10:
0321955048

ISBN 13:
978-0-32195-504-3

29

$21^2+20^2=x^2$
$441+400=x^2$
$841=x^{2}$
$\sqrt {841}=x$
$29=x$, because $29\times29=841$

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