Question

measure of positive angle coterminal - 3pi/2 degrees

Answer 1

Assuming the angle is -3π/2 (radians): add 2π to get a positive coterminal angle:

-3π/2 + 2π = (-3π + 4π)/2 = π/2.

So a positive coterminal angle is π/2 (which is 90°).

(Generally coterminal angles differ by integer multiples of 2π: θ + 2kπ.)