Question

the sides of a triangle have length x,x + 4, and 20. if the length of the longest side is 20, which value of x would make the triangle acute

Answer 1

its 14 on edg

Answer 2

See below.

Explanation:

If the triangle is right-angled then x = 12 and x + 4 = 16, because 20^2 = 12^2 + 16^2.

In an acute triangle if c is the hypotenuse then c^2 < a^2 + b^2 so x must be greater than 12. Also as 20 is the longest side x cannot be 16 or greater.

So pick a value greater than 12 and less than 16.