Help w/ triangles: length of one leg is 8 cm less....

[mandora1]

The length of one of the equal legs of an isosceles triangle is 8 cm less than 5 times the length of the base. If the perimeter is 30 cm, find the length of one of the equal legs :x

 

[Mrspi]

Re: Help!!

The length of one of the equal legs of an isosceles triangle is 8 cm less than 5 times the length of the base. If the perimeter is 30 cm, find the length of one of the equal legs :x

Let x = length of the base

Then, the length of each of the equal legs is "8 less than 5 times the base", or 5x - 8.

Ok...
base is x
one leg is 5x - 8
other leg is 5x - 8

perimeter is 30

Add up the three sides and set the sum equal to 30, the perimeter.

Solve for x....but remember, you're asked to find the length of one of the legs, so you'll have to evaluate 5x - 8 for the value of x you get.

I hope this helps you.