Calculate Spheical Cap with areaquad

Hi,

Tried to calculate the surface area of a spherical cap with areaquad

I wrote the following code:

R=100;

TH=30

dTh=TH*pi/180;

Zone2= areaquad(90,0,TH,360)*4*pi*R^2

h=R-R*cos(dTh);

Zone1=2*pi*R*h (taken from http://mathworld.wolfram.com/SphericalCap.html)

If you run the code the areas are not the same.

I even tried:

Zone2= areaquad(0,0,TH,360)*4*pi*R^2

Do you know why?

Shani