Question

The lengths of the sides of an equilateral triangle are 3(x + )cm, (5x +2y-1) cm and 5x +1 Cm Find the side length of the triangle. ​

Answer 1

Correct option is A

Since it is an equilateral triangle, the lengths of the sides are equal

So, x+3 y=3 x+2 y−2=4 x+

2

1

​

y+1

x+3 y=3 x+2 y−2

y=2 x−2

2 x−y=2 ...(1)

Also, 4 x+

2

1

y+1=x+3 y

8 x+y+2=2 x+6 y

6 x+2=5 y

6 x−5 y=−2 ...(2)

Multiplying e q(1) by 5 we get,

10 x−5 y=10 ...(3)

Subtracting e q(2) from e q(3) we get,

4 x=12⇒x=3

y=2 x−2=4

The length of one side of equilateral triangle = x+3 y =3+3(4)=15 units