To find out if a triangle is a right triangle, you can use the Pythagorean theorem(which can only be used for right triangles):
a² + b² = c² (c is the hypotenuse or the longest side) And you can plug in the side lengths into this equation. If they are the same number on both sides, it is a right triangle, if they are different numbers it is not a right triangle.
6.) a² + b² = c²
(4√3)² + (11)² = (13)²
(16(3)) + 121 = 169
48 + 121 = 169
169 = 169 It IS a right triangle
7.) a² + b² = c²
(5)² + (2√14)² = (9)²
25 + (4(14)) = 81
25 + 56 = 81
81 = 81 It IS a right triangle
8.) a² + b² = c²
(6)² + (√49)² = (√82)²
36 + 49 = 82
85 = 82 It is NOT a right triangle
9.) a² + b² = c²
(13)² + (2√39)² = (16)²
169 + (4(39)) = 256
169 + 156 = 256
325 = 256 It is NOT a right triangle
