1) is this something new with him?
2) how was he at 2 years old?
3) is it only with things that he 'can't' do, that he gets angry?
4) does he nap?
5) does he get enough sleep?
6) Is his 'anger' something more than just the typical/normal three year old behavior?
7) Is there something new/traumatic in his life, that he may be having a hard time adjusting to?
8) does he go to daycare/preschool?
9) How do you handle him when he gets this way?
When a child, 'cannot' do something, they naturally get frustrated/tantrum.
These are some things that you have to consider, in light of his 'anger' as you mentioned.
Keep in mind, that 3 years old is much harder than 2 years old... because it is a transition age, and they are going through so so many developmental changes. ie: at this age, they are expected to behave like a 'big boy' but yet...they are still 'baby' in terms of their cognition and ability to 'cope' and their developmental maturity AND emotional maturity. It's growing pains for the child... then the parent gets frustrated. The child is not understood.
Now, a 3 year old still needs help to get dressed. If for example he is 'expected' to just change clothes himself and get dressed himself... then a child naturally gets frustrated. And if they are rushed and hurried along, MOST kids get fussy and tantrum. Kids need TIME to get ready, and to have a lead-time to get ready. BUT... if he is just wanting to get dressed himself and insists on it... this is normal too, at this age. At this age, they want to do things themselves...BUT, their coordination and what their mind is telling them versus their actual 'ability' to do it, is two DIFFERENT things. Thus, a child gets frustrated. This too is normal.
Also, a child this age, does not have 'coping skills.' Thus, they erupt, get frustrated, tantrum. They also have emotions which are STILL developing... so they can't possibly juggle all of these things and be sane about it all. They are trying to figure it all out. Its a time of contradictions. Ability versus the inability to do things. THey are still learning.
Just a word of warning: "tantrums" and frustrations of a child, does not end at 2 years old. Many say the 'terrible 2's' are hard... but actually 3 and 4 years old is STILL an age where there WILL be tantrums. By 5-6 years old, it settles down. Because the child is more emotionally 'mature' at these ages... and more capable, and they can communicate better. Then when pre-teen and at teen ages, they get like this too, but in a different way. Their "maturity" is STILL developing, and their abilities.
Also, if a child is 'expected' to behave a certain way, versus what they actually can do... then a child gets 'stressed.' Thus, tantrums and frustration/anger. Then, the Parent has to take the CUES of the child, and help them or comfort them. Its all about going according to your child... and keeping expectations AGE-APPROPRIATE. If for example, and 3 year old is expected to behave like a 5 year old, it won't work... and the parent and child will always be frustrated.
If your child tantrums doing tasks... help him through it. Don't just tell him "quiet", "no", "stop it", "grow up" etc. It will NOT help. (I'm not saying you do these things, just as an example).
For me, with my 2 kids... each child is different in their abilities. And I don't expect "perfection", just doing their best even if it is not 'perfect.'
Sometimes, instead of just scolding, try and put yourself in his shoes? What is he going through? Why? What is triggering it? How can you coax him through it? Is he getting praised enough? Or is he just told what to do? Maybe, he gets frustrated getting dressed, because there are TOO many choices. MANY kids, get overwhelmed if there are too many choices... so, just get out 2 outfits, and ask him "Do you want to wear this blue shirt, or this green one?" Then that's all. Don't leave him to do the whole dressing process by himself. A 3 year old can't do that. Now, an outfit does not have to "match" either. If he wants to wear something that to you, does not match, then fine. A child needs to learn this too, and have their own learning curve and self motivation.
Sometimes kids also get this way, because they can never do it good enough, like how they imagine in their heads. So... it's a process too, they have to learn. Maybe at this point, help him identify 'feelings' so that he can tell you how he feels... and express himself. Then a child feels understood. If my kids feel angry or frustrated... I don't tell them they can't. Instead I say "I know, you feel frustrated/angry... Mommy feels like that too sometimes. What can we do to make it better?" Then, talk about it with him. And sometimes a kid just needs to vent. Just like adults.
Try and distract him, when he gets angry/frustrated. Change the mood... and the expectations of him. Make funny songs about getting dressed, make rhymes, act goofy... and make dressing "fun." Maybe this is a task that gets him grumpy... because he needs help to do the task. No matter how 'smart' a child is... their emotional and cognitive 'maturity' is STILL that of a child. Again, it's all about ages and stages, and age appropriate expectations.
Anyway, just some thoughts, sorry for rambling...
All the best,