Angles of elevation and depression

Angle:
Angle is called the geometric figure formed by two lines starting from a common point.

Measuring angles: the magnitude of the angles is called the degree

Sexagesimal: Divide the circle into 360 equal parts and each of these parties is a sexagesimal degree

Circular system: the Radom which is equivalent to the amplitude produced by an arc of circumference equal to the magnitude of the radius.

Positive angle: when the line is counterclockwise

Angle of elevation: angullo is measured from the horizontal upward.

Depression angle: the angle to be measured below the horizontal.

Angles between parallel cut by a transversal or transversal parallel CUNADO 2 are cut by a transversal are distinguished 8 pairs of equal angles to each other.

If you cross a line intersects two parallel lines, alternate interior angles are those between the parallels to other side of them and other side of the transversal.
The angles 2 and 3 are equal

Internal conjugate angles
Angles are not adjacent, situated in one half-plane with respect to the tangent, both are internal. Are supplementary angles.
^ ^
A + A = 180 º
^ ^
ð + å = 180 º

Side or internal angles:
They are on the same side of the cross, but otherwise the parallels are also complementary:

Pythagorean Theorem:

He says the second of the sum of the hypotenuse equals the sum of the squares of its legs.

The bisectors of a triangle are the lines perpendicular to each of the sides at their midpoints.
The intersecting point where the three bisectors of a triangle is called the circumcenter and the center of the circumcircle.

The altitudes of a triangle are the lines that go from a vertex perpendicular to the opposite side.

The altitudes of a triangle are the lines that go from a vertex perpendicular to the opposite side.
The intersecting point where the three altitudes of a triangle is called orthocenter.

The bisectors of a triangle are the lines that divide each of the other two equal angles.

The bisectors of a triangle are the lines that divide each of the other two equal angles.
The intersecting point where the three bisectors of a triangle is called incenter and is the center of the inscribed circle.

The medians of a triangle are the lines that go from one vertex to the midpoint of the opposite side.

The intersecting point where the three medians of a triangle is called the centroid.

Draw two triangles and one isosceles equilateral one and determines the circumcenter, the orthocenter, the incenter and the centroid.