Answer:
AB=[tex]75m[/tex]
Step-by-step explanation:
In the [tex]\Delta SCB[/tex] and [tex]\Delta SDA[/tex]
[tex]\angle S=\angle S\\BC||AD\\\Rightarrow\angle SBC=\angle SAD\\\angle SCB =\angle SDA[/tex]
[tex]By\ AAA\ \Delta\ and\ \Delta SDA\ are\ similar\\\\ \Rightarrow\frac{SC}{SD} =\frac{SB}{SA} \\\\ \frac{80}{180} =\frac{60}{SA}\\\\ SA=60\times\frac{180}{80} \\\\SA=135\\\\AB=SA-SB\\\\=135-60\\\\=75m[/tex]
