18 is 20% of what number

20%   of a number means  

20/100    of a number.  

20/100=0.2 we can say that  

 0.2

x

, where  

x

is a number we don't know,  

=

18

.

0.2

x

=

18

Divide both sides by  

0.2

.

x

=

90

We can check this by finding  

20 %

of  

90

and seeing that it is equal to  

18

.

90(0.2)=18

Step-by-step explanation:

imma say 16%. sorry if its wrong. i'm doing the same stuff right now

step-by-step explanation:

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.