Which of the following instruments is T-shaped?

3.
Rulers are used for measuring dimensions of objects.
The correct option is (c).

• (a) Dividers are used for transferring measurements or dividing lines.
• (b) Drawing paper is a surface for drawing.
• (c) Rulers are used for measuring lengths and drawing straight lines.
• (d) Protractors are used for measuring angles.

The final answer is $\boxed{\text{rulers}}$.

20.
A Tee square is a T-shaped instrument.
The correct option is (b).

• (a) A try square is L-shaped.
• (b) A Tee square is a T-shaped instrument used in technical drawing.
• (c) A protractor is typically semicircular or circular.
• (d) Dividers have two pointed legs.

The final answer is $\boxed{\text{Tee square}}$.