SAT Geometry
Dr. John Chung’s SAT Math
Angles Review
| Angle CMB = Angle AMD Angle AMD + Angle CMA = 180o |
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Example of SAT question with angles:In the figure below, angle AMB is 100o, angle BMD is 40o and angle CME is 60o. What is the value of angle CMD? Figure not drawn to scale 
(a) 20o
(b) 30o
(c) 40o
(d) 50o
(e) 80o
Answer: If angle AMB is 100o, then angle BME is 180o – 100o = 80o BMC + CMD = 40o BMC + CMD + DME = 80o If we subtract the 2 equations, DME = 40o CMD + DME = 60o BMC + CMD + DME = 80o If we subtract the 2 equations, BMC = 20o CMD = BME – BMC – DME = 80o – 40o – 20o = 20o
Parallel Lines Review
| If the 2 horizontal lines are parallel, – angles 1 = 3 = 5 = 7 and – angles 2 = 4 = 6 = 8 |
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Polygons Review
| The sum of the measures of the interior angles of a triangle is 180°. a + b + c = 180o |
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| The sum of the measures of the interior angles of a polygon is: (n – 2)·180o n = number of sides of the polygon. |
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The sum of the measures of the interior angles of the polygon above is (5 – 2)·180o = 540o
| AC2 = AB2 + BC2. |
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Pythagorean Theorem applied to the triangle above: AC2 = AB2 + BC2.
| Equilateral triangle. a = b = c = 60o AB = BC = CA |
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| Isosceles triangle. b = c AB = AC |
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| a> c > b. BC > AB > AC |
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In any triangle, the longest side is opposite the largest angle, and the shortest side is opposite the smallest angle.
Area, Perimeter and Volume
| Rectangle Perimeter 2·a + 2·b Rectangle Area a·b |
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| Triangle Perimeter AB + BC + CA Triangle Area (h/2)·BC |
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| Circle Perimeter 2·¶·r Circle Area ¶·r2 |
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| Cube Volume a3 |
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| Cylinder Volume h·¶·r2 |
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Examples of SAT Geometry Questions GED Practice Exemple of SAT Subject geometry problem