Answer:
x = 16.8
Explanation:
To get the value of x, we use Pythagoras’ theorem since what we have is a right angled triangle
Mathematically, we have it that;
the square of the hypotenuse (21) equals the sum of the squares of the two other sides
21^2 = 12.6^2 + x^2
x^2 = 21^2 - 12.6^2
x^2 = 282.24
x = √282.24)
x = 16.8