Answer:
problem 1:
angle a is obtuse, angle b is acute, angle c is obtuse, angle d is right
problem 3:
triangle a is scalene, triangle b is equilateral, triangle c is isosceles, triangle d is isosceles.
problem 5:
a) triangle
b) circle
c) rectangle
problem 2:
triangle a is obtuse, triangle b is obtuse, triangle c is acute, triangle d is right.
problem 4(answers in orders):
figure a, none, figure c
Hope this helped!