Question

the length of a room is 3 more than its breadth if the area of the floor of the room is 70 metre square then find the perimeter of the floor​

Answer 1

The perimeter of the floor is 34m.

Since the length and breadth are unequal, we can consider it to be a rectangle.

Let the breadth be B m

Length =( B+3 )m

So the area is = Length* Breadth = (B+3)*B = B^2 + 3B

Area is given as 70, so we can write B^2 + 3B = 70

Or, B^2 + 3B - 70= 0

Or, B = -10, +7 ( since breadth can't be a negative value, we take +7)

Length= 10m, Breadth= 7m

So, the perimeter = 2( Length+ Breadth) = 2(10+7) = 34m.

Answer 2

Answer:

perimeter of the floor = 34 m

Step-by-step explanation:

Let the breadth of the room be "a" m

length of the room is 3 more than its breadth,

=> length = (a + 3) m

Given,area of the floor of the room = 70 $m^{2}$

         length × breadth = 70

            a (a + 3) = 70

            a² + 3a = 70

            a² + 3a - 70 = 0

            a² + 10a - 7a - 70 = 0

        a(a + 10) - 7(a +10) = 0

            (a + 10) (a - 7) = 0

          => a = 7 and a = -10

dimension cannot be negative so a = 7

breadth of the room = 7 m

length of the room = 7 + 3 = 10 m

Perimeter of the floor = 2(length + breadth)

                                    = 2(7 + 10)

                                    = 2 (17)

                                    = 34 m