The lengths of the sides of a triangle are in the ratio 5:6:7. What is the length of the longest side if the perimeter is less than 54 cm?

I don;t know im not good at math

7*3 = 21 cm

Answer < 21 cm

If they are in the ratio of 5:6:7, then their lengths would be:

5x, 6x, and 7x where x is some real number.

We want the perimeter to be less than 54 cm, so we can set up an inequality that adds up the lengths of the three sides, and compares it to this max length, then solve for x. then use that figure out what the longest side could be:

5x + 6x + 7x < 54

18x < 54

x < 3

Multiply that by 7 to get:

7x < 21

So the longest leg is some value less than 21 cm to keep the perimeter less than 54 cm.