A regular tetrahedron (an equilateral triangular pyramid).
6 faces 1o edges and 8 corners
It has to be 90 degrees and yes, straight.
a right angle is half of a straight angle
A straight angle is an angle that is 180 degrees exactly (a straight line). A right angle is 90 degrees (like the corners of a square.)
A right angle because 180* - 90* is 90* which is a right angle !
6 faces 1o edges and 8 corners
It has to be 90 degrees and yes, straight.
It is used to mark or scribe lines at 90 degrees (right angle) to a straight edge. Also used to check two adjacent edges are at 90 degrees (right angle)
a right angle is half of a straight angle
Right angle (90) < Obtuse angle < Straight angle (180)
Acute angle=45 degrees Right angle = 90 degrees Straight Angle=180 degrees.
None of the angles between edges are greater than 90o - they are all 90o as each face is a square with a right angle at each corner, and each face is at right angles to the faces to which it is joined.
Straight angle
A straight angle is an angle that is 180 degrees exactly (a straight line). A right angle is 90 degrees (like the corners of a square.)
An acute angle is an angle less than 90 degrees. A right angle is 90 degrees. A straight angle is a straight line. For example: take a 90 degree angle and straighten it out to form a line, and it becomes a straight angle.
It has 4 faces, 4 corners, and 4 edges, but two edges are different from each other. All the corners are right angles.
A right angle because 180* - 90* is 90* which is a right angle !