MATLAB: There is a difference between trignometry and matlab answers

Question

we know that

radian ×pi/180=degree but when i calculated sin(90) that is 0.8940 and multiplied it like sin(0.8940×pi/180) give me 0.0156 not 90

Answer 1

sin(90*pi/180)

or

sind(90)

Your current calculation is

sin(sin(90) * pi/180)

where the sin(90) is 90 radians.