You can put this solution on YOUR website! You can classify an angle x in one of three ways:
i) acute x<90
ii) right x = 90
iii) obtuse x>90
Given that, let's answer your questions:
1) 24. 24<90 so acute
2) 98 > 90 so obtuse
3) 126 > 90 so obtuse
4) 90=90 so right