Answer:
x =21.4
Explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 b^2 =c^2
The leg are a and b and the hypotenuse is c.
In the triangle pictured, the legs are x and 18 and the hypotenuse is 28
x^2+18^2 =28^2
x^2 +324 =784
Subtract 324 from each side
x^2 +324-324 = 784-324
x^2 =460
Take the square root of each side
sqrt(x^2) = sqrt(460)
x =21.44761059
Rounding to the nearest tenth
x =21.4