Graduate Management Admission Test (GMAT)
Geometry
Lines
Line - a straight line that extends in both directions with no end.
Line segment - a part of a line, usually marked by 2 endpoints.
Endpoint - each line segment has 2 endpoints.
Intersecting Lines and Angles
Vertical angles where 2 lines intersect are equal.
Perpendicular Lines
Right angle = 90°. If 2 lines cross at right angles they are perpendicular.
Parallel Lines
These are two lines in the same plane that do not intersect.
Polygons
A closed figure made up of 3 or more line segments. Each interior angle is less that 180°. A triangle is a 3-sided polygon, a square is a 4 sided polygon, etc.
Perimeter - found by adding the length of all the sides together.
Triangles
Property of ALL triangles - the sum of the length of ANY 2 sides of the triangle is greater than the length of the other.
Equilateral triangle - all 3 sides are of the same length.
Isosceles triangle - at least 2 sides are of the same length.
Right angle triangle - a triangle containing a single 90 angle.
Hypotenuse - the side opposite the right angle in a right angle triangle.
Pythagorean Theorem - in a right angle triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the other two sides. This formula
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04/30/02
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Graduate Management Admission Test (GMAT)
may be used to work out the length of the third side of a triangle in which the lengths of the other two sides are known.
Area of a triangle = 12 bh
where b is the length of the base and h is the height of the triangle.
Quadrilaterals
A 4-sided polygon is a quadrilateral.
Here are some quadrilaterals:
•Square
•Parallelogram
•Rectangle
Trapezoid - a 4-sided polygon in which one pair of opposite sides have equal length
Area of trapezoid = 12 (sum of bases) x height
Parallelogram - a 4 sided polygon in which both pairs of opposite sides have equal Length
Area of parallelogram = base x height
Rectangle - a 4-sided polygon in which opposite sides have equal length and all angles are 90°.
Area of rectangle = base x height
Square - a 4-sided polygon in which all sides have equal length and all angles are 90°.
Area of square = base x height
© 2002 All Rights Reserved – BrainBuzz.com
04/30/02
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Graduate Management Admission Test (GMAT)
Circles
Chord - a line segment that has endpoints on the circle.
Diameter - the distance across the circle through the center.
Radius - the distance from the center to the edge of the circle (half the diameter)
Circumference of a circle = 2πr, where π is 3.142… and r is the radius of the circle.
Area of a circle = πr 2 , where r is the radius of the circle.
Tangent - a line that touches the circumference of a circle at a single point.
Rectangular Solids and Cylinders
Rectangular solid - made up of 6 rectangular faces.
Surface area of a rectangular solid = the sum of the area of all 6 faces.
Volume of a rectangular solid = length x base x height.
Cylinder - made up of 2 circular faces and a tube joining them (like a pop can). Surface area of a cylinder = sum of the area of the 2 circular faces plus the area of the tube (treat as a rectangle, using the circumference of a circular face as base or height)
Volume of a cylinder = πr 2 h, where r is the radius of a circular face and h is the height of the cylinder.
Coordinate Geometry
X axis - the horizontal line
Y axis - the vertical line
Origin - the point where the X and Y axis meet.
Coordinates - given in an ordered pair of numbers (x,y)
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04/30/02
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