Answer:
3√10
Explanation:
27² + y² = x²
⇒⇒⇒ y² = x² - 27² ----------------- [ 1 ]
3² + y² = z²
⇒⇒⇒ y² = z² - 3² ----------------- [ 2 ]
Equate [ 1 ] and [ 2 ] :
x² - 27² = z² - 3²
x² - z² = 27² - 3²
x² - z² = 720 ----------------- [ 3 ]
x² + z² = 30²
x² + z² = 900 ----------------- [ 4 ]
[ 3 ] - [ 4 ] :
-2z² = -180
z² = 90
z = √90
z = 3√10