How can I build muscles in my arms, stomach, and legs?

I'm a really skinny, tall 17 year old guy (6' ; 145 lbs) I have decent arm muscles, but the rest of my body is just mediocre. I want to know some really good ways to build muscle in my arm/shoulder, stomach/chest, and leg/calf areas. Also, if you could tell me how long it would take for even the slightest... show more I'm a really skinny, tall 17 year old guy (6' ; 145 lbs) I have decent arm muscles, but the rest of my body is just mediocre. I want to know some really good ways to build muscle in my arm/shoulder, stomach/chest, and leg/calf areas. Also, if you could tell me how long it would take for even the slightest results to show, that would be helpful. Any tips or advice is appreciated, Thank you all very much.
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