What track should I take if I love arts and mathematics?

You may also want to consider anatomy and physiology in addition to architecture. I am not sure what kind of art you are particularly interested in, but having a background in biology, I can definitely Say that having an artistic nature is an asset in the life sciences.

First I'll give you some practical and "sensible" advice. Focus on mathematics. It has wide-ranging applications and prospects for gainful employment and good pay. There are many, many areas that require mathematics, and engineering applications being a lot of them, it has the potential to benefit many people every day.

Now I'll give you a "happy" answer, and I don't mean to downplay this. If you do what you like, you'll likely be good at it. And if you're good at something, you have the most potential to help the most people. And here's the kicker: Mathematics and art are a match made in heaven. These days, applying artistic concepts finds a helpful hand in computers and architecture and manufacturing and designing of ergonomic tools and just about every beautiful construct and solution that the world needs. So if you love art and you pursue mathematics, you'll find yourself indulging in artistic pursuits all the time. And you'll have the most likelihood of finding ways to merge these all the time.

One example that you'll be confronted with frequently is the commercial applications of art being drawn to engineering and general STEM concepts. Look at the most beautiful songs or movies or art or architecture or just about every technical product in the world. You'll see a lot of them that exhibit that catch-phrase engineers and scientists use for beautiful solutions and designs: "Sexy". When an engineer or scientist talks bout a "sexy" solution, they're talking elegance. The thing that makes your heart jump when you see it. It could be a math formula or a cool car or a beautiful building or a wonderful orchestration of a musical piece.

Now my personal opinion -- that some may find controversial, but hey, it's my opinion -- is that if you pursue art, you would be less likely to also pursue math with the same vigor, but if you pursue mathematics, you'll be drawn to art compulsively. At least I found that in myself. I used every scientific invention or projects as opportunities to explore the "sexy" solutions and artistic approaches to problem solving. I suspect you will too.

There are a lot of valuable factoids in those other answers, but I'd like to offer some personal experience. When I was taking grad courses in computer engineering, I took a course from a guy named Sproull (other computer people might recognize this). He wrote a book about computer graphics and it was terrific. He was also involve in the design of the first Alto computer that the Mac was based on. He knew all the math, all the algorithms and seemed to be just ecstatic about the whole art/computer combination thing.

What I would recommend, in light of the close coupling of arts and computing and math today is to choose either math or art and minor in the other. The fact that music and movies and art and all the rest is so closely coupled today, and the fact that you really can't experience any of them without seeing that a lot of it was made on computers and using exotic mathematics is proof that you really won't be able to avoid math and computers today if you love art. Also, some of the most beautiful things I've seen in life are so exquisitely mathematical, that I don't think you could possible go wrong.

One thing that I have been heavily involved with over the last 3+ years is Data Visualization using Tableau. I enjoy using Tableau as it allows me to be creative with visual design instead of producing boring reports. Check out Tableau Public online to see how math and art come together with Tableau.