# 7: Geometry


• 7.1: Angles
An angle is the figure formed by two rays with a common end point, The two rays are called the sides of the angle and the common end point is called the vertex of the angle.
• 7.2: The Area of a Rectangle and Square
The measurement of the area of geometric figures is one of the most familiar ways mathematics is used in our daily lives. The floor space of a building, the stae of a picture, the amount of paper in a roll of paper towels are all examples of Items often measured in terms of area. In this chapter we will derive formulas for the areas of the geometric objects which we have studied.
• 7.3: The Area of a Triangle
The base can be any state of the triangle though it is usually chosen to be the side on which the triangle appears to be resting. The height is the line drawn perpendicular to the base from the opposite vertex. Note that the height may fall outside the triangle, If the triangle is obtuse, and that the height may be one of the legs, if the triangle is a right triangle.
• 7.4: Pythagorean Theorem
In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the legs.

Thumbnail: Similar Triangles. (CC BY-SA 3.0; Nguyenthephuc via Wikipedia).

This page titled 7: Geometry is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Henry Africk (New York City College of Technology at CUNY Academic Works) .