what is the convention for positive rotation

What is the convention for a rotation of 90 degrees where neither clockwise nor anticlockwise are explicitly stated? Is a rotation of 90 degrees assumed to be 90 degrees anticlockwise as the explanation for one question in 8th grade geometry seems to say?
I was thinking that "a rotation of 90 degrees" meant 90 degrees clockwise so I got it wrong but it just feels wrong to have anticlockwise being positive as the convention.

https://www.khanacademy.org/math/cc-eighth-grade-math/geometric-transformations
Properties & definitions of transformations
Mapping Shapes