For rhombus A:
base = 7 in
area = 35 in²
Area of rhombus = b * h
⇒ 35 = 7 * h
⇒ h = 35/7
⇒ h = 5 in
Rhombus B:
height = 3*5 = 15 in
base = 7*3 = 21 in
Area = 15 * 21 = 315 in
Area of rhombus B is 9 times area of rhombus A. When the dimensions are increased to 3 times the initial dimension, area became 9 times.