Help hurry i really need help on this quick

first one because it can't have a fraction in it

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.

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x