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Mathematical geometry problems in the second volume of the seventh grade
Solution: ① ∠ m =1/2 (∠ b+∠ d) = 35;

(2) As shown in the figure: ∫AM, CM divides ∠BAD and ∠BCD equally,

∴∠BAM=∠MAD,∠MCB=∠MCD,

∠∠ANC =∠b+∠BAM =∠M+∠MCB,∠AEC=∠MCD+∠D=∠MAD+∠M,

∴∠m=∠b+∠bam-∠mcb①,∠m=∠mcd+∠d-∠mad②,

∴ ①+②: 2∠M=∠B+∠D,

∴∠M= 1/2(∠B+∠D)。