Today I did the Linear Functions + Inequalities (Hard) set with a 21/23. The questions I got wrong are: 8c5e6702 and 5bf5136d. Can someone pls give me an explanation for the second one (second picture) cz how is one supposed to know that the third side of the triangle is greater that the difference of the other two sides if they are not familiar with the triangle inequality theorem nor is it mentioned in the question. Is it something one is supposed to know? thanks