: ● 1 ● 3 ● 3/4 ● 1/2 ● 1/2 ● ● 3/4 , ( ) : 1. (, ) , , 5 , , , . 2. 180. , . ( 10). , . 3. 6 , . . 4. , , . 5. , 45 , . , .