1. Flip triangle ADF over triangle BCE such that A is over B and F over E to get both angles alpha and beta at vertex E. 2. By definition of trigonometric ratio, side/trig ratio = the other side of the trig ratio. Hence rearrange the equations to the form of side/trig. ratio on both sides. 3. Choice I is to get hypotenuses of triangles. Obviously they are different and not equal. 4. Choice II & III are to get bases of triangles. The bases are a common base hence must be equal.
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1. Flip triangle ADF over triangle BCE such that A is over B and F over E to get both angles
alpha and beta at vertex E.
2. By definition of trigonometric ratio, side/trig ratio = the other side of the trig ratio.
Hence rearrange the equations to the form of side/trig. ratio on both sides.
3. Choice I is to get hypotenuses of triangles. Obviously they are different and not equal.
4. Choice II & III are to get bases of triangles. The bases are a common base hence must be
equal.
Thank you so much!終於識做呢種題型，以前亂撞😂
唔駛客氣! 幫到你就好啦:D