Try to learn the examples. Although the sentences may have a couple of equivalents in Persian, I have given you one of them to make it easier for you. The Persian sentences below (1-4) are the exact equivalents of the second English sentences. Enjoy your drills!
1- This ruler is 50 centimeter long = the length of this ruler is 50 centimeter. 
/tu:l e in khæt kesh pænja:h sa:nti metr æst/.
2- This room is 3 meters wide = the width of this room is 3 meters. 
/ærz e in ota:gh seh metr æst/.
3- This wall is 2 meters high = the height of this wall is 2 meters. 
/ertefa: e in diva:r do metr æst/.
4- This water is 1 meter deep = the depth of this water is 1 meter. 
/omgh e in a:b yek metr æst/.
5- I will wait for you near that square. 
/mæn næzdik e a:n meida:n montæzeræt kha:hæm bu:d/.
Note:
If you are talking about shapes, you could simply add the word 
/beh shekl e/ like below.
6- This table is square. 
/in mi:z beh shekl e moræb.bæ æst/.
7- The football field / ground is rectangle (rectangular). 
/zæmin e fu:tba:l beh shekl e mostætil æst/.
8- This paper is triangle. 
/in ka:ghæz beh shekl e mosæl.læs æst/.
9- The backgammon dices are cubical. 
/ta:s e tækhteh nærd beh shekl e mokæ.æb æst/.
Note:
In such sentences (6-9), you could simply delete /beh shekl e/ and add 
to the end of each shape.
Example:
This paper is triangle. 
/in ka:ghæz mosæl.læsi æst/.
I hope it was not difficult for you.
See you next week.