1) ABCD is a parallelogram such that the bisectors of ∠A and ∠B meet on CD. Prove that AB = 2BC.
Please answer the second and third by using mid-pt theorem or intercept theorem.
2) D is the mid-pt of the side BC of △ABC; BR, CS are the perpendiculars freom B, C to any straight line passing through A. Prove that DR = DS. 1) Take case when the line through lies outside ∠BAC. 2) Take case when it lies inside ∠BAC (Hint: Draw the perpendicular DK from D to RAS.)
3) D is the mid-pt of the side BC of △ABC; CA is produced to E. If BR is the perpendicular from B to the busector of ∠BAE, prove that DR = 1/2 (AB + AC).
THX
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