Start by adding together the shortest two sides, 7 and 8.7 inches. Result: 15.7 inches. Because this sum is greater than the longest side, 15.4 inches, it's possible to construct a triangle, whose largest angle will be close to 180 degrees.
Supplementary Angles are two angles the sum of whose measures is 180º. Supplementary angles can be placed so they form a linear pair (straight line), or they may be two separate angles.
