No, obtuse angles are not smaller than ninety degrees as they are larger than one ninety degrees (from the initial side to the terminal side) yet smaller than one hundred and eighty degrees.

Remember, any angle larger than a right angle is an obtuse angle. For example, a 90.0000001 degree angle would still be considered obtuse angle. On the other hand, an obtuse angle should not be confused with a reflex angle, which exceeds one hundred and eighty degrees (you will learn about reflex angles later).

One rule to always remember is that a straight angle (exactly 180 degrees) is not considered obtuse as it is categorized in its own type of angle.

Obtuse angles are larger than 90 degrees and less than 180 degress, so your assumption is wrong. An angle less than ninetry degrees is called an acute angle. See the picture below for an example of an obtuse angle, notice that it is larger than a right angle.

...No, obtuse angles are angle that are above 90. Acute angles are angles below 90. I used to remember them by the small ones are cute, so their acute, and the opposite is obtuse.

Hope this helps.

No, an obtuse angle is between 90, and 180 degrees.

An acute angle is less than 90 degrees.

A right angle is equal to 90 degrees.

Obtuse angles are larger than 90 degrees but smaller than 180 degrees. Acute angles are smaller than 90 degrees.

...An obtuse angle is always larger than ninety degrees, but always smaller than 180 degrees.

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