All of the angles in a rectangle are right angles.
Yes. The sum of the angles in a triangle is 180° All angles in a triangle must be greater than 0° which means that the sum of any two angles must be less than 180° If two angles are right angles (90°), their sum is 180° which is not less than 180°; thus at most one angle can be a right angle. If one angle is a right angle and another is an obtuse angle (greater than 90°), then their sum is greater than 180°, which is not less than 180°; thus there can be at most one of a right angle and an obtuse angle. If two angles are obtuse angles, their sum is greater than 180°, which is not less than 180°; thus there can be at most one obtuse angle. If there is at most one right angle or an obtuse angle, there must be at least two acute angles.
Convex : all angles less than 180 degrees. Concave: at least one reflex angle (greater than 180 deg).
Each interior angle of a regular pentagon is 108 degrees ie all five of them are larger than a right angle. If the pentagon is convex, at least four of the angles must be greater than 90 degrees.
Yes it must have at least one (really, it needs two or more). The sum of the interior angles in a pentagon is 540°. If you had 4 angles @ 90°, then the fifth angle would need to be 180°, which is a straight line, then it would be a rectangle, not a pentagon, so you need at least two angles, greater than 90°.
Yes, but not on this site. All triangles must have at least two acute angles. Take one of these and the exterior angle associated with it will meet your requirements.
The angles between adjacent sides of a polygon that are interior to the polygon. If the polygon is convex, the interior angles are always less than 180 degrees. If it is concave, at least one interior angle will be greater than 180 degrees.
A concave polygon is a polygon with at least one interior angle greater than 180 degrees. This causes the polygon to have at least one "dent" or indentation in its shape. The presence of these interior angles greater than 180 degrees distinguishes concave polygons from convex polygons, which have all interior angles less than 180 degrees.
There are as many interior and exterior angles as there are sides (the line segments that make up the polygon. The sum of each pair of exterior angle and interior angle is 180 degrees, i.e. they are supplementary. For concave polygons, there will be at least one "negative" exterior angle paired with an interior angle of greater than 180 degrees - the total of the angles is still 180 degrees.
No, because complementary angles are two angles whose sum is 90 degrees.An obtuse angle is greater than 90 degrees and less than 180 degrees.
It is a triangle
No. A triangle can have only one obtuse angle. A triangle must have at least two acute angles
Yes, because the angles have to add up to 360º, at least one angle has to be obtuse.