Question

déterminez le nombre de faces, de sommets et darêtes qui constituent ce solide et remplissez le tableau ci - dessous. faces, sommets, arêtes et relation deuler nombre de faces (f) :? nombre de sommets (s) :? nombre darêtes (a) :? f + s - a :?

Explanation:

Step1: Count the faces

The base is an octagon (8 - sided polygon) and there are 8 triangular faces connecting the base to the apex. So the number of faces $F=8 + 1=9$.

Step2: Count the vertices

The vertices of the base octagon are 8, and there is 1 apex vertex. So the number of vertices $S=8 + 1=9$.

Step3: Count the edges

The base octagon has 8 edges, and there are 8 edges connecting the apex to the vertices of the base. So the number of edges $A=8+8 = 16$.

Step4: Calculate $F + S - A$

Substitute the values of $F = 9$, $S = 9$ and $A = 16$ into the formula $F+S - A$. We get $9+9 - 16=2$.

Answer:

Nombre de faces ($F$): 9
Nombre de sommets ($S$): 9
Nombre d'arêtes ($A$): 16
$F + S - A$: 2