Question

The three branches of government have powers that overlap each other. this federal design is called _____.

Answer 1

The fact that the government is divided into three branches is known as the "division of power"  - the power is distributed to avoid power abuse, so that no instance has unlimited power.

The fact that the three branches are overlapping is known as "checks and balances" - the branches check the other  ones (whether their function is lawful) and balance each other.