Geometric mean (1 Viewer)

[enigma_1]

Help, how do you do these questions? Especially the first one?

 

[asianese]

They basically want you to show that

 

[enigma_1]

YeH im stuck on that

 

[RealiseNothing]

YeH im stuck on that

The triangles are similar. Whenever you have similar triangles and you want to prove something to do with the sides (in this case ) it should ring alarm bells that you have to use the ratio of the sides.