Question

Need help bad! Number 21 to be exact.

Answer 1

#21)
Using Pythagorean Theorem a^2 + b^2 = c^2
so
a^2 = c^2 - b^2


x^2 = 42^2 - 38^2
x^2 = 1764 - 1444
x^2 = 320
 x =√320
 x = √(64 * 5)
 x = 8√5

Answer 2

  A^2+B^2=C^2
A^2+38^2=42^2
A^2+1444=1764
       -1444=-1444
          A^2=320
A=the square root of 320
A=the square root of 16*20
A=4 the square root of 20

Hope this helps!!