Which one of the following is an AutoCAD relative polar co-ordinate: (b) @81,30 (c) 30<81 (d) @81<30 ?

Thanks for the invite. Sorry, the question is out of my field.

Answer is: option (d) @81<30

the answer is (D) this is the correct co ordinates

the answer

 @ 81 <30

More than one method can be written @ then the length of the piece then> then the angle

Command: l LINE

Specify first point:

Specify next point or [Undo]: @ 500 <30

It is also possible from Polar

Draw a line and then right click on polar

Dialog Box Write the appropriate angle

And they are caught under the polar and chosen by you and painted

Option D is the right choice.

thanks for the invite the anwer is d 

@81<30

Thank you for the invitation

Agreed with Option D

With greetings and appreciation