BAC
where the middle letter is the vertex, A
where A is the vertex, or x where
x is located inside the angle.
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1. Angles and Lines
2. Intersecting Angles
3. Triangles
4. Circles
5. Perimeters & Areas
6. Solids
7. Coordinate Geometry
Angles and Lines
An
angle is formed when two line segments intersect. The point of
intersection is the vertex and the two lines form
the sides of the angle. The angle is designated
in a number of ways. It is BAC
where the middle letter is the vertex, A
where A is the vertex, or x where
x is located inside the angle.
BAC
There are special kinds of angles:
A) Acute angles are less than 90
B) Obtuse angles are greater than 90 C) Right Angles are exactly 90 D) Complementary Angles are two angles that sum to 90
E) Supplementary Angles are two angles that sum to 180 (or a straight line).
Example 1
An incident ray strikes a flat surface and is reflected at the same angle. If the angle between the reflected ray and the incident ray is three times the angle of incidence, what is the angle of incidence?
Solution
The below sketch of the incident ray and the reflected ray is helpful.
If x is the angle of incidence, then x + x + 3x = 180
