Try to draw rough sketches of
(a) a scalene acute angled triangle.
(b) an obtuse angled isosceles triangle.
(a) a scalene acute angled triangle. :
Scalene : All side of different length
Acute angled : All angles less than
(b) an obtuse angled isosceles triangle
Isosceles traingle: Only two sides are of equal length
Obtuse angled : At least one angle greater than