Answer:
Step-by-step explanation:

BC = 15 cm
3x = 15
x = 15/3 = 5
AB =4x = 4*5 = 20 cm
Pythagorean theorem,
AC² = AB² + BC²
= 20² + 15 ²
= 400 + 225
= 625
AC = √625 = 25 cm
AC = 25 cm

Try this suggested option (all the details are in the attachment), the correct orientation is marked with red and green colours.
P.S. The point C has coordinates: (3;1). If to traslate it 6 units right and 5 units down, then (3+6;1-5) ⇒ (9;-4). The same principle is for the others points A, B and D. Note, after translation point A is point E, B⇒F, C⇒G and D⇒H.
Uh I’d don’t know try to multiply them together to see what you get
L + W
length plus width
example: L = 10" W = 20" 10 x 20 = 200