PRESENTATION OUTLINE
Acute Angle
An angle smaller than 90°bigger than 0°
Obtuse angle
Bigger than 90°less than 180°
Right angle
90°angle that is less than 180°
Straight angle
A angle that is exactly 180° a straight line
Vertical angle
Vertical Angles are the angles opposite each other when two lines cross. They are always equal.
Adjacent angle
Adjacenangles are Adjacent when they have a common side and a common vertex (corner point), and don't overlap.
Complementary angle
Complementary
Two Angles are Complementary when they add up to 90 degrees (a Right Angle) . They don't have to be next to each other, just so long as the total is 90 degrees ...
Supplementary angle
An angle that adds up to be 180°
Corresponding angle
Corresponding Angles. When two lines are crossed by another line (called the Transversal): The angles in matching corners are called Corresponding Angles. In this example, these are corresponding angles:
Transversal angle
a transversal intersects two parallel lines, then the alternate interior angles are congruent. If not then one is greater than the other, which implies its supplement is less than the supplement of the other angle.
Acute triangle
In an obtuse triangle, one angle is greater than a right angle—it is more than 90 degrees. An obtuse triangle may be isosceles or scalene. In an acute triangle, all angles are less than right angles—each one is less than 90 degrees. An acute triangle may be equilateral, isosceles, or scalene.
Right triangle
A right triangle or right-angled triangle is a triangle in which one angle is a right angle (that is, a 90-degree angle). The relation between the sides and angles of a right triangle is the basis for trigonometry.
Obtuse triangle
The indicated angle is larger than 90 degrees. Both triangles are obtuse because they contain an angle greater than 90 degrees. No matter where in the triangle that angle is, as long as it's greater than 90 degrees, the triangle containing it is obtuse.
Scalene triangle
A scalene triangle is a triangle that has three unequal sides, such as those illustrated above.
Isosceles triangle
In geometry, an isosceles triangle is a triangle that has two sides of equal length. Sometimes it is specified as having two and only two sides of equal length, and sometimes as having at least two sides of equal length, the latter version thus including the equilateral triangle as a special case.
Equilateral triangle
The three sides of any equilateral triangle are equal. The three angles of any equilateral triangle all measure 60 degrees.