Can someone help me ​

Step-by-step explanation:

we need to use pythagoras's theorem (reversed) in this situation. We know the hypotenuse and the lower line, so we can find the upright one. That will be the value of AD.

so we use 81 (9 squared) and 144 (12 squared)

let x be the upright line's length

144-81=x squared

63=x squared

find the square root of 63 and you can have your answer

Im not gonna do that for you because that's pretty easy

13.46

step-by-step explanation:

16.80 x .20 = 13.46