8.7 you need to do the Pythagorean theorem
You were given one side length and the hypotenuse so your equation should b 18^2+x^2=20^2
To me it is C. or D. but you would need a second opinion. Sorry.
15 because 3/4 is equivalent to 75% and 75% of 20 is 15.
The answer is c!!!!!!!!!!!!!!!!!!!!!!!!
