Here we are, talking about the second to last man body shape, the triangle man.
Unlike the relative female shape, this male kind of body should be better compared to the diamond female body shape.
Triangular shaped men have an ectomorphs body classification, which is often a slender figure with narrow shoulders and chest, low fat mass, a long neck and sloping shoulders. When a triangular shaped man puts on weight that will be distributed among the abdomen, chest and face and can sometimes look out of proportion to the rest of the body. As for the rectangle body shape, this kind of body also can have an hard time gaining lean muscles.
Long story short what we have here is: sloping shoulders, long limbs, chest narrower than hips, so lower body area heavier than upper part.
Of course there are many ways to create “optical illusions” to balance this kind of body as well.
What we are going to do here is to enlarge the chest and drive the attention on it, and in order to achieve this result you need to wear straight shirts (and jumpers and whatsoever) then remember, never go too slim but never too loose as well.
Now remember that horizontal stripes give an “enlarging” look so use them to make your chest look broader; don’t be shy and wear printed tops, especially those where printings are located in the shoulders/chest area.
Also layering your clothing on your upper body will work well. And try to use light colors or at least colors lighter than the one you’re going to use for your trousers.
Use padded jackets has you will need those pads to balance your figure, prefer double breasted jackets and coats, in particular those with large flaps, with pockets or zips on the chest or, in case of long coats, go for the ones with big pockets because big pockets make big butts and hips look slimmer.
Same rule can be applied to rear jeans pockets, and please, stick to tapered models, or with a bit flared leg because those are a good option too as they can help hide large thighs and balance out larger hips. The fastenings on the jeans should be nice and neat (or banned sounds better to me) to avoid any extra bulking. Waist must be regular or high and pick dark colors, no light washed jeans please.
Let’s talk about shirts now: you need to find the collar that goes with your shape, the best collars for you, a medium spread collar and a standard straight point collar, in light shades of colors, possibly with pockets on the upper part.
Trousers instead shouldn’t be pleated and I know it’s very hard to find a not pleated nice pair of trousers so at least pick those broader on the top, with a regular straight fit leg that can be slim from the knee down or still ends regular straight.
In conclusion, a last tip about coats and jackets, go short (not lower than the hips) or go long (below your knee line). No half measures.