Anglo-Chinese School (Primary) P5 SA2 2006 Math Question (Q39)

Two identical big squares A and B overlap to form a small square of area 36 square cm. The ratio of the shaded area to the unshaded area is 1 : 6. Find the length of x.

Solution


(Shaded Area) 1 unit ----- 36 square cm.
(Unshaded Area) 6 units ------ 36 square cm x 6 = 216 square cm.


Area of 1 large square is
(216 square cm divided by 2) + 36 square cm
= 144 square cm.

Length of side of large square is

144 square cm = 12 cm x 12 cm


Answer: The length of x is 12 cm.