Quick needed, need someone to check my answer.

mario’s company makes unusually shaped imitation gemstones. one gemstone had 12 faces and 20 edges. how many vertices did the gemstone have?
a. 34 vertices
b. 10 vertices (my answer)
c. 30 vertices
d. 8 vertices

The answer is B. 10 vertices because it all depends on the edges. You have to subtract the edges by faces/vertices to get your faces/vertices so 20-12 is 10 so you are correct

7.3

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.