By definition, euler's formula is given by: C + V = A + 2 Where, C: number of faces V: number of vertices A: number of edges Substituting values we have: 21 + V = 49 + 2 Clearing V we have: V = 49 + 2-21 V = 30 Answer: the missing number is: A. 30
Question 2:
The volume of the cube is: V1 = L1 ^ 3 = 512 The volume of the new cube is: V2 = L2 ^ 3 = 3375 V2 = (kL1) ^ 3 = 3375 V2 = k ^ 3 (L1) ^ 3 = 3375 V2 = k ^ 3V1 = 3375 Therefore, the scale factor will be: k ^ 3 = V1 / V2 k ^ 3 = 512/3375 k = (512/3375) ^ (1/3) k = 8/15 Answer: the scale factor of a cube with a volume of 512m ^ 3 to a cube with a volume of 3,375 m * 3 is: A. 8:15