English architect and polymath Robert Hooke was the first to build the Gregorian telescope invented by which Scottish mathematician?
Gregorian telescope: The Gregorian telescope is a type of reflecting telescope designed by Scottish mathematician and astronomer James Gregory in the 17th century, and first built in 1673 by Robert Hooke. Robert Hooke: Robert Hooke FRS ( ; 28 July [O.S. 18 July] 1635  – 3 March 1703) was an English natural philosopher, architect and polymath.
James Gregory