Points, lines, planes
Angles
Acute, obtuse, right
Complementary, supplementary, right
Angles made by transversals
Triangles
Sum of angles
Types of triangles
Identified by angles
acute, obtuse, right
Identified by sides
scalene
Attitude, mean, bisector
Congruent triangles
Pytheogoreum theory
Special right triangles
Polygons
Basic terms
Plane shapes
Sum of angles
Interior angles
Exterior angles
Square, rectangle, rhombus
Parallelograms
Trapezoid
Perimeter and area
Square
Rectangle
Parallelogram
Triangle
Trapezoids
Circle
Terms
Pi
Perimeter and area
Solid Shapes
Square area and volume
Prism
Cuboid and cube
Cylinder
Pyramid
Cone
Sphere
Co-ordinate geometry
Points and co-ordinates
Co-ordinates and axes
Ordered pairs
Quadrants
Distance formula
Mid-point formula
Slope of a line
Equation of a line

Basic Terms and Shapes of Geometry
Geometry is the study of points, lines, and planes and their relationships to each other in time and space and the concepts and� the terms used to express
them.
Angles and Their Measures
Angles are measured in degrees and are classified by their measure. The three classifications of angles are: acute, right, and obtuse. An acute angle has a
measure of less then 90 degrees. An obtuse angle has a measure greater then 90 degrees. A right angle measures 90 degrees. Angles have special
relationships.
Complementary and Supplementary Angles
Two angles are complementary if their measures, added together, equal 90 degrees, and two angles are supplementary if their measures, added together,
equal 180 degrees.
Types of Congruent Angles
The three types of congruent angles are:
Vertical angles - two nonadjacent angles formed by two intersecting lines.
Alternate interior angles - a pair of nonadjacent angles, both are on the interior and on the opposite sides of the transversal.
Corresponding angles - a pair of nonadjacent angles, one interior and one exterior, and both on the same side of the transversal.
Pythagorean Theorem
A right triangle is a triangle with one right angle. If you know the lengths of two sides of a right triangle, use the Pythagorean Theorem to find the third side.
The Pythagorean Theorem states that the length of the hypotenuse squared is equal to the sum of the squares of each leg. a^2 = b^2 + c^2
Triangles
Triangles are classified either by their sides (scalene, equilateral, or isosceles) or their angles (obtuse, right, or acute). Three methods of proving triangles are
congruent are:
SSS - side side side
SAS - side angle side
ASA - angle side angle
Quadrilaterals
A quadrilateral is a figure with four sides. There are some special types of quadrilaterals and they are:
Trapezoid - one pair of parallel sides
Parallelogram - two pairs of parallel sides
Rectangle - A parallelogram with four right angles
Rhombus - a parallelogram with four congruent sides
Square - a parallelogram with four right angles and four congruent sides
Circles
Terms related to circles include center, radius, diameter, chord, secant, and arc.
Perimeter
The perimeter is the distance around an object. To find the perimeter, add the lengths of all sides together.
If the figure is a rectangle use this formula:
P = 2l + 2w (2 times the length plus 2 times the width)
If the figure is a square use this formula:
P = 4s (4 times the length of any side)
Area of Parallelograms
A parallelogram is a quadrilateral shape in which opposite pairs of sides area parallel and equal. The area of a parallelogram is the number of square units that
covers its surface.
A = bh����� Area = base*height
Area of Triangles
To find the area of a triangle use this formula:
A = - bh / 2 (area equals 1/2 base times height or base times height divided by 2)
Area of Trapezoids
To find the area of a trapezoid use this formula:
A = - h/2(b + b )� Area equals height divided by 2 times the sum of the bases.
Circumference and Area of Circles
In a circle the distance across the circle is the diameter, 1/2 the distance across the circle is the radius and the distance around the circle is the circumference,
The formulas for finding circumference are:
C = d(pi)��� circumference = diameter times pi where pi = 3.14
C = 2r(pi)�� circumference = 2 times radius times pi
Volume of Rectangular Prisms and Pyramids
Volume is the amount of a space an object contains. To find the volume of a rectangular prism, use this formula:
V = lwh (Volume equals length times width times height)
To find the volume of a rectangular pyramid, use this formula:
V = - lwh/3 (Volume equals length times width times height divided by 3)
Volume of Cylinders and Cones
Use 3.14 for pi
To find the volume of a cylinder, use this formula:
V = (pi)r^2h� (volume equals pi times radius squared times height)
To find the volume of a cone, use this formula:
V =� - (pi)/3r^2h� (volume equals one-third of pi times 3 radius squared times height)