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1, ,2,S = ab,S = ah2,S = ah,S = aa, , = , = , = 2, = ,3,1. ,2. ,3. ,4. , :：,4,5, 。, , , 。,6,12dm,8dm,7dm, ,7,: ,8,9, 。, ,10,11,12,13,14,15, , ,16,( + ), , , ,S=（a + b）h 2, = 2, = ( + ) 2,17,12dm,8dm,7dm,S=(a+b)h 2 =(12+8)72 =2072 =70(d),18,14cm,26cm,8cm,S=(a+b)h2 =(14+26) 82 =4082 =3202 =160(c), 14 26 8 ,19, ,20, 36 . ,21,（, 2.,（, ( ), .( ), .( ), ( ).,22,C,A,B,D,E,287 = 4（mm）,73 = 4（m）,S =（ab）h2,=（74）42,= 22（）, ABCD 28 AB AE 3 BCDE ,23, 3 50 ,14m,24,14m,S=(a+b)h2 =(50-14)142 =36 142 =252(), 3 50 ,25, m, 80 ,26, 18 , 88 ,27, ,28, , 2 ,29,