Need some help please and thank u

The discount is 8.70 . you dont tell us the percent of tax added so there is no way to find out, unless i'm not seeing anything. without tax its 37.70

The sum of the angles in a triangle is 180°. this is called the angle-sum property.the sum of the lengths of any two sides of a triangle is greater than the length of the third side. similarly, the difference between the lengths of any two sides of a triangle is less than the length of the third side.the side opposite to the largest angle is the longest side of the triangle and the side opposite to the smallest angle is the shortest side of the triangle.