Bunuel
What is the area of rectangle ABCD?
(1) The length of side AB is 2 units more than the length of side BC.
(2) The length of the diagonal AC is 10 units.
Solution
Step 1: Analyse Question Stem
• We need to find the area of rectangle ABCD.
o Area of a rectangle \(= length * breadth = AB*BC\)
So basically, we need to AB*BC (or the product of any two adjacent sides) of ABCD.
Step 2: Analyse Statements Independently (And eliminate options) – AD/BCE
Statement 1: The length of side AB is 2 units more than the length of side BC.
• \(AB = BC + 2\)
• So, \(Area = AB*BC = (BC+2)*BC\)
• However, we don’t know BC so we cannot find the area.
Hence, statement 1 is NOT sufficient and we can eliminate answer Options A and D.
Statement 2: The length of the diagonal AC is 10 units.
• It means, \(AB^2 + BC^2 = 10^2\)
• But we cannot find AB and BC from here and hence we cannot find AB*BC
Hence, statement 2 is also NOT sufficient and we can eliminate answer Option B.
Step 3: Analyse Statements by combining.
From statement 1: \(AB – BC = 2\)
From statement 2: \(AB^2 + BC^2 =10^2\)
On combining the two statements, we can write,
• \((AB – BC)^2 = 4 ⟹ AB^2 + BC^2 – 2AB*BC = 4 ⟹10^2 - 2AB*BC = 4\)
Hence, we can find \(AB*BC\).
Thus, the correct answer is
Option C.