An angle which is equal to 90 degrees is known as ____.
acute angle
right angle
obtuse angle
reflex angle
An angle which measures less than 90 degrees is a/an _____.
If one angle of a triangle is less than 90 degrees, it is known as an acute-angled triangle.
State whether the following statement is true or false.
If one angle of a triangle is greater than 90 degrees, it is known as an obtuse-angled triangle.