Two sides of a triangle have lengths 10 and 15. What must be true about the length of the third side? less than 25 / less than or equal to 25 / equal to 25 / more than 25

The length of the third side of a triangle is always less than the sum of the other two legs. Therefore if we add the two legs we obtain,

leg 1 + leg 2

10 + 15 = 25

Since the sum of the legs is 25, thus, the third leg should be less than 25.