Verified answer

~ учить - to learn (generally), and/or to learn something this very moment:

- What are you doing? - I'm doing physics homework.

- Что ты делаешь? - Я делаю домашнее задание по физике.

But very often pupils say: Я учу физику - lit.: I'm learning physics (history, biology etc)

~ учиться - is a reflexive verb form of учить,

~ изучать - to study/learn something, it indicates the particular subject you're taking in college or uni: biology, physics, philosophy etc...

учить - to teach or to be in the process of learning - depends on the context. Учить танцам - to teach someone to dance, учить разные танцы - to learn various dances.

изучать - to study, to examine. Изучать математику - to study maths, изучать черты лица - to examine the features of one's face.

учиться - to learn, to study. Учиться танцевать - to learn how to dance. Учитьcя в школе - to study in a school.

Semantically учить, учиться, изучать and to learn, to study have multiple meanings, sometimes those meanings coincide, sometimes - they don't.