What picture........................
All the sides add like a rectangle with two sides measuring 4 and two measuring 2 so you would add 4+4+2+2=12
By the converse of the Pythagorean Theorem, if 8.6 ^2 = 8.1 ^2 + 2.6 ^2 , then the triangle is right. 73.96 is not equal to 72.37 so the triangle is not a right triangle.
8.6^2 is greater than (8.1^2 + 2.6^2) which means that the triangle is obtuse.
The obtuse angle is opposite the 8.6 side.
ANSWER—C.................................