I think the correct answer is A.
Multiplication, addition, subtraction
Step-by-step explanation:
1. Right angled triangle , scalene triangle
2. isosceles triangle, obtuse angled triangle
3. equilateral triangle
4. right angled triangle, isosceles triangle
5. scalene triangle, obtuse angled triangle
6. scalene triangle, acute angled triangle
(X+4)^2-15
This is the answer
921÷ 2 = 460.5
which means the remainder is 1
So; the answer is 1
