See Figure 4 below.
1. Draw a 7-carbon chain and number the carbon atoms (Figure 1).
2. Insert a triple bond between atoms 5 and 6 (Figure 2).
3. Attach a phenyl group to atom 3 (Figure 3).
4. Attach a Br to atom 1 (Figure 4).
And you have your structure.
Note: The C≡C triple bond takes priority in the naming, so we must number the chain from the other end. The correct name is
7-bromo-5-phenylhept-2-yne (all one word).