Slopes of Perpendicular Lines 垂直線的斜率(1)

Explore the conditions of the slopes for perpendicular lines.

English version: http://www.geogebratube.org/material/show/id/3449 (Download GeoGebra file)

Drag C so that the two lines are perpendicular to each other.

What is the relationship between their slopes?

http://www.geogebratube.org/material/show/id/3449

探討兩線垂直時的斜率關係。

中文版: http://www.geogebratube.org/material/show/id/15486 (Download GeoGebra file)

相關工作紙 及教育局「網上學與教支援」資源（中文版）

拖拉紅色 C 點，令兩線垂直。

兩垂直線的斜率有甚麼關係？

http://www.geogebratube.org/material/show/id/15486