Answer:
The missing length is: 19.4
Step-by-step explanation:
according to pythagorean theorem, a^2 + b^2 = c^2
the hypotenuse is 21 and side and the short leg is 8
c²-b²=a²
21²-8²
441-64
377
take the square root of 377
it is 19.41
which rounds to 19.4
x=19.4
