Answer:
45°
Step-by-step explanation:
MA is the diameter of the circle.
[tex] \therefore m\widehat {MTA} =180\degree [/tex]
[tex] m\widehat {TA} =m\widehat {MTA} -m\widehat {MT} [/tex]
[tex] \therefore m\widehat {MT} =180\degree -45\degree [/tex]
[tex] \therefore m\widehat {MT} =135\degree [/tex]
[tex] m\angle S =\frac{1}{2} (135-45)\degree [/tex]
[tex] m\angle S =\frac{1}{2} \times 90\degree [/tex]
[tex] m\angle S =45\degree [/tex]
