There are no acute angles in a rectangle which has 4 equal interior right angles
18
An angle must have 2 sides or it is no longer an angle.
If you mean a polygon with equal exterior angles of 18 degrees then it will have 360/18 = 20 sides.
15
there are only two sides.
Two side are equal
1 acute angle = 1 acute angle
It has 3 sides It has 3 exterior angles that add up to 360 degrees It has 3 interior angles that add up to 180 degrees It has a perimeter which is the sum of its 3 sides It has an area which is: 0.5*base*perpendicular height It has no diagonals It will tessellate It can be a scalene triangle having 3 different acute angles It can be an obtuse triangle having 1 obtuse angle and 2 different acute angle It can be a right angle triangle having a 90 degree angle and 2 acute angles It can be an isosceles triangle having 2 equal sides and 2 equal acute angles It can be an equilateral triangle having 3 equal sides and 3 equal 60 degree angles It is subject to the rules of trigonometry
None, two or three
A square has four equal sides and four equal angles.
An acute angle has one angle.
There are triangles that are named for relationships of their side lengths: scalene has no equal sides Isosceles has 2 equal sides, and equilateral has all 3 sides equal. Then there are names for relationship of angles. Acute has all 3 angles less than a right angle (90°). Right has one angle is a right angle (90°). Obtuse has one angle greater than 90° but less than 180°. An equilateral triangle has all three angles 60°, so it is also acute. An acute triangle can be scalene or isosceles, as well. A right triangle can also be either scalene or isosceles. An obtuse triangle can also be scalene or isosceles.
For the "catch all" and most broad type of triangles, there are 3: Obtuse - 1 angle > 90° Acute - all angles < 90° Right - 1 angle exactly 90° There are more specific categories, such as isosceles triangles, which can be obtuse, right or acute triangles that contain exactly 2 angles of equal degree, and exactly 2 sides of equal lengths.
There are infinitely many angles which are acute.
All angles will be equal and the type of angle will depend on how many sides the shape has
An acute angle is less than 90 degrees. Dividing a square into four equal triangles would not have any acute angles since they would all be 90 degrees. A 90 degree angle is called a right angle.