PROBLEMS. 

 t»ROBLEM XXI. 



403 



^0 niah a 'Triangle nvith three given Lines A B, AC, B C» 



"With the centre A and radius 

 A C, describe an arc. "With 

 the centre B and radius B C, 

 describe another arc cutting the 

 former in C. Draw AC and 

 B C, and ABC is the triangle 

 required. 



c 



PROBLEM XXII. 

 To make a Square upon a given Line A B. 



Draw BC perpendicular and 

 -equal to AB. From A and C, 

 with the radius AB, describe 

 arcs Intersecting in D. Draw 

 A D and C D, and it is done. 



3> 



J-^ 



Another Way, 



On the centres A and B, 

 with the radius A B, describe 

 arcs crossing at o. Bisect A o 

 in «. With centre o, and rad- 

 ius ony, cross the two arcs in C 

 and D. Then draw AC, 

 B D, C D, 



i> 



/ "^ IX 



j.-^ 



B 



PROBLEM 



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