Length of wall is 16 feet and breadth is 4 feet.
Step-by-step explanation:
- Step 1: Given area = 64 sq. ft, length is breadth + 12 ft. Let breadth be b.
So length, l = b + 12
- Step 2: Substitute in area for rectangle = length * breadth
⇒ (b + 12) * b = 64
⇒ b² + 12b = 64
⇒ b² + 12b - 64 = 0
- Step 3: Solve for b using equation for finding roots of quadratic equation
Roots = (- b ±√b² - 4ac)/2a
⇒ b = (- 12 ±√144 - 4 * 1 * - 64)/2
= (-12 ±√144+256)/2 = (-12±√400)/2
= (-12±20)/2
= 4, -16 (negative is neglected)
⇒ breadth is 4 feet
- Step 4: Length = b + 12 = 16 feet
