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vertex; apex
top (e.g. of a mountain); summit; peak
top (of a profession, field, etc.); summit
peak (of popularity, a boom, etc.); height (e.g. of prosperity); apex; zenith; climax
三角形の頂点から底辺に線を引いた。
I drew a line from the vertex of the triangle to the base.
選手は世界大会で頂点に立った。
The athlete reached the top at the world championships.
彼は人気の頂点にいたときでした。
He was at the peak of his popularity.