Answer: it is a
Step-by-step explanation:
The answer is obtuse
a = 4
b = 28
c = 31
If a² + b² > c² - the angle is acute
If a² + b² < c² - the angle is obtuse
If a² + b² = c² - the angle is right
a² + b² = 4² + 28² = 16 + 784 = 800
c² = 31² = 961
800 < 900
a² + b² < c²
Therefore, the angle is obtuse
To find the answer to -10x=-210 you must divide -210 by -10
-210/-10= 21
Therefore x=21
So the proper equation is -10(21)=-210
