E URGENT!!!!!!!!!!!!!!!!!

Cu teorema lui Pitagora se determină AB=12 cm.
SB=20-8=12cm ; CT=16:2=8cm
Triunghiurile SAB și SCT sunt isoscele.
[tex]\it Din\ \Delta SAB \Rightarrow \widehat{ASB}= \dfrac{180^o-\hat B}{2}\\ \\ \\ Din\ \Delta SCT \Rightarrow \widehat{TSC}= \dfrac{180^o-\hat C}{2}\\ \\ \\ \widehat{ASB}+ \widehat{TSC}=\dfrac{360^o-(\hat B+\hat C)}{2}=\dfrac{360^o-90^o}{2}=135^o[/tex]
[tex]\it \widehat{AST}=180^o-( \widehat{ASB}+ \widehat{TSC})=180^o-135^o=45^o[/tex]