12 MISC. PUBLICATION 22 5, U. S. DEPT. OF AGRICULTURE 



Table 19. — Area of large circles with equivalent in squares J 



Radius of 



Side of 



Area in 



Area in 



circles 



squares 



square feet 2 



acres 



Feet Inches 



Feet Inches 







3 8.7 



6 7.2 



43.6 



0.001 



5 



8 10.3 



78.5 



.0018 



5 7.7 



10 



100 



.0023 



6 



10 7.6 



113.1 



.0026 



7 6 



13 3.5 



176.7 



.0041 



8 



14 2.2 



201.1 



.0046 



10 



17 8.7 



314.2 



.0072 



11 3.4 



20 



400 



.0092 



11 9.3 



20 10. 5 



436 



.01 



12 6 



22 1.9 



491 



.0113 



12 7.4 



22 4.3 



500 



.0115 



15 



26 7.0 



707 



.0162 



17 10. 1 



31 7.5 



1000 



.0230 



18 7.4 



33 



1089 



.025 



25 



44 3.7 



1963 



.0451 



26 4.0 



46 8.0 



2178 



.05 



28 2.5 



50 



2500 



.0574 



30 



53 2.1 



2827 



.0649 



30 10. 8 



54 9.3 



3000 



.0689 



32 3.0 



57 1.9 



3267 



.075 



33 



58 5.9 



3421 



.0785 



35 8.2 



63 2.9 



4000 



.0918 



37 2.8 



66 



4356 



.1 



37 6 



66 5.6 



4418 



.1014 



39 10. 7 



70 8.5 



5000 



.1148 



50 



88 7.5 



7854 



.1803 



52 7.9 



93 4.1 



8712 



.2 



58 10. 5 



104 4.3 



10890 



.25 



64 5.9 



114 3.8 



13068 



.3 



66 



116 11.8 



13685 



.3142 



67 11.8 



120 6. 



14520 



.33^ 



69 1.2 



122 5. 7 



15000 



.3444 



74 5.7 



132 



17424 



.4 



79 9.5 



141 5. 1 



20000 



.4591 



83 3.2 



147 7. 



21780 



.5 



101 11.7 



180 9. 



32670 



.75 



117 9.0 



208 8. 5 



43560 



1 



The value in heavier type is that from which the corresponding values were computed. 

 Area iu square feet equals 3.141592654 times radius in feet squared. 



Table 20 



. — Number of trees per acre 



by various methods of spacing 



Spacing (feet) 



Trees 



Spacing (feet) 



Trees 



Spacing (feet) 



Trees 



2X2 



Number 



10, 890 



4,840 



2,722 



2,178 



1,815 



1,556 



1,361 



1,210 



1,089 



1,742 



1,452 



1,245 



1,089 



968 



871 



1,210 



1,037 



908 



807 



726 



605 



484 



889 



778 



7X9 



Number 

 691 

 622 

 519 

 415 

 681 

 605 

 544 

 454 

 363 

 218 

 538 

 484 

 403 

 323 

 436 

 363 

 290 

 242 

 360 

 330 

 264 

 198 

 158 

 302 



12X15 



Number 

 242 



3X3 -- 



7X10 



12X18 



202 



4X4 



7X12 .-- 



12X20 



12X25 



182 



4X5 



7X15 



145 



4X6 - 



8X8 



13X13. , -- 



258 



4X7 



8X9 



13X15 



223 



4X8 - 



8X10 .... 



13X20 



13X25 



168 



4X9 



8X12- - -.. 



134 



4X10 



8X15 



8X25 .-. 



14X14 



14X15 - . . 



222 



5X5 - 



207 



5X6 



9X9 



14X20 



14X25 



156 



5X7 



9X10 



124 



5X8 



9X12 -- 



15X15 -- 



194 



5X9-- 



9X15 



10X10 ._- 



15X20 



145 



5X10 - - 



15X25 



116 



6X6 



10X12 



16X16 



170 



6X7 



10X15 



10X18 



16X20 



16X25 



136 



6X8 



109 



6X9 



11X11 



18X18 



18X20 



134 



6X10 



11X12 



121 



6X12 - .- - 



11X15 - 



18X25 



97 



6X15 



11X20 



20X20 



109 



7X7 



11X25 



20X25 



87 



7X8 



12X12 



25X25 .. 



70 











