Intersection of circles – How can I reduce this golf code to 127 bytes?
Use Python 2's arg unpacking: 124 bytes



from math import*;circleIntersection=lambda(v,w),(x,y),r:r*r*(lambda h:h&lt;1and acos(h)-h*(1-h*h)**.5)(hypot(v-x,w-y)/r/2)//.5


Try it online!

Python 2 has parameter unpacking, allowing the input point arguments to be taken directly as pairs (v,w) and (x,y), where the input lists like [0,0] and [0,10] will be unpacked into the respective variables. This feature was removed in Python 3 -- a pity, in my opinion, since the old syntax seems more readable. But, the site has a Python 2 option, and nothing in your solution relies on Python 3.