Final answer:
The Constitution improved on the Articles of Confederation regarding the legislative branch by establishing a bicameral legislature with proportional representation in the House of Representatives and equal representation in the Senate.
Step-by-step explanation:
The Constitution improved on the Articles of Confederation regarding the legislative branch by establishing a bicameral legislature with proportional representation in the House of Representatives and equal representation in the Senate. Under the Articles of Confederation, the national legislature was unicameral and each state had an equal vote, regardless of population. The Constitution's bicameral legislature allowed for a more balanced representation and ensured that both large and small states had a voice in the legislative process.