Two sides of a triangle have the same length. the third side measures 3 m less than twice that length. the perimeter of the triangle is 21 m. find the lengths of the three sides.

The lengths of three sides are 6 m, 6 m and 9 m.

Step-by-step explanation:

Given:

Two sides of a triangle have the same length.

The third side measures 3 m less than twice that length.

The perimeter of the triangle is 21 m.

Now, to find the lengths of all three sides.

So, naming the three sides of triangle a, b, and c.

As given two sides of a triangle have the same length.

So, let the first side of triangle(a) be

And the other side(b) be same

Now, the third side(c) be

Perimeter = 21 m.

Now, putting formula to get the sides:

Adding both sides by 3 we get:

Dividing both sides by 4 we get:

Now, getting the sides of triangle by putting the value of :

a = 6 m.

b = 6 m.

c =

Therefore, the lengths of three sides are 6 m, 6 m and 9 m.

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.