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If O is the outer center of the acute triangle ABC and Ao, Bo and co intersect with L, m and N respectively, then Ao: Al + Bo: BM + CO: CN=
Let o be OE ⊥ BC, then let a be AF ⊥ BC, then let f be AF ⊥ BC, AF ⊥ BC, ∥ OE ∥ AF, ∥ OEL ∥ AFL, ∥ ol ∶ al = OE ∶ AF. the △ OBC and △ ABC are triangles with the same base and different heights, ∥ OE ∶ AF = the area of △ OBC ∥ the area of △ ABC, ∥ ol ∶ al = the area of △ OBC ∥ the area of △ ABC
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