 Hello and welcome to the session. Today I will help you with the following question. The question says verify Euler's formula for this solid. First let's discuss what Euler's formula is. Euler's formula is F plus V minus E is equal to 2 where F is the number of faces of the polyhedron. V is the number of vertices of the polyhedron. E is the number of edges of the polyhedron. This is taken as the key idea for this question. Let's move on to the solution. Consider the figure given to us. Now let's see what the number of faces that is F for this figure is. Now this is one face 4, 5, 6, 7 is the base, 8 is this and 9 so total number of faces is 9. Now let's find out the number of vertices that is V is equal to this is 1 vertex 2, 3, 4, 5, 6, 7, 8, 9. So in all number of vertices that is V is equal to 9. Next we are supposed to find the number of edges of this figure that is E and this is equal to this is one edge 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16. So E becomes equal to 16. By Euler's formula we have F plus V minus E is equal to 2. We will consider the LHS that is F plus V minus E. Now we substitute the values for F, V and E. This becomes equal to F is 9 plus V is 9 minus E is 16 which is further equal to 9 plus 9 is 18 minus 16 and that is equal to 2 which is equal to RHS of the Euler's formula. Thus we have LHS is equal to the RHS so we say that Euler's formula is verified. So hope you enjoyed the session. Have a good day.