Y=mx+b,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Step-by-step explanation:
Find the gradient of AB
-2.5
Find the gradient of perpendicular
0.4
Make the equation
y= 0.4x + c
Apply point A
3= 0.4*2+c
3-0.8= c
c= 2.2
y= 0.8x + 2.2
Sin∠R = ST/RS ⇒ ST = RS * sin40° = 9 * 0.6428 ≈ 5.8
I think The side is 90 in