Vertices of a solid shape is a point where 2 lines or edges of the shape intersects. If tom has a cube a rectangular prism and a triangular prism, then the cube has 8 vertices, a rectangular prism has 5 vertices (a rectangle has 4 vertices plus the point where all the lines coming from the vertices of the rectangle intersects).
Also, a triangular prism has 4 vertices(a triangle has 3 vertices plus the point where all the lines coming from the vertices of the triangle intersects)
Hence the only shape that has more than 6 vertices is a cube.
Step-by-step explanation: 4 1/2 meters is too short, he would have to buy 2 lengths. 4 1/2 meters is 450 cm while 9 meters is 900 cm, if he gets the 900 cm length he can just cut off the excess to use later.