Question

:)Answer in simplest radical form.(and show work please)

Answer 1

Explanation:

Use Pythagorean theorem,

Base² + altitude² =hypotenuse²

x² + 19² = 21²

x² + 361 = 441

x² = 441 - 361

x² = 80

`x =√(80)=√(2*2*2*2*5)=2*2*√(5)=4√(5)`