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GRE Math: Angles And Triangles

Instructions:

Answer 37 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. median
Line drawn from any angle of a triangle to the midpoint of the opposite side
26
Extend one side of the triangle
A line that bisects (halves) an angle in a triangle

2. 15-20-?
SAS SSS ASA SAA HL
26
Less than 90
25

3. obtuse angle
More than 180
More than 90 but less than 180
SAS SSS AAA
41

4. acute/obtuse triangle
17
.5B*h
5
Angles less than 90/between 90 and 180

5. 5-12-?
A line that bisects (halves) an angle in a triangle
61
13
8

6. congruent triangles
180
Two angles totalling 180
SAS SSS ASA SAA HL
More than 180

7. vertical angles
Opposite angles formed when two lines cross
Angles less than 90/between 90 and 180
25
29

8. Following is true about isosceles triangles
Opposite angles formed when two lines cross
61
At least 2 equal sides
The base may be equal - greater or less than any other side - the legs are equal - angle across base is the vertex angle (+><) - base angles are equal

9. 3-4-?
61
5
Line segment from a vertex perpendicular to the base
25

10. 12-16-?
20
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
Get shorter leg first - shorter leg is half hyp - to find short leg given hyp - div by 2 - to find hyp given short leg - *2 - find short leg given hyp - div by sqrt3 - find long leg given short leg - *sqrt3
5

11. isosceles triangle
At least 2 equal sides
61
SAS SSS AAA
All equal sides

12. 6-8-?
More than 90 but less than 180
Extend one side of the triangle
At least 2 equal sides
8

13. 7-24-?
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
25
3 unequal sides
Opposite angles formed when two lines cross

14. straight angle
Line segment from a vertex perpendicular to the base
180
S^2*sqrt(3)/4
SAS SSS AAA

15. acute angle
All equal sides
Less than 90
Extend one side of the triangle
SAS SSS AAA

16. exterior angle
Get shorter leg first - shorter leg is half hyp - to find short leg given hyp - div by 2 - to find hyp given short leg - *2 - find short leg given hyp - div by sqrt3 - find long leg given short leg - *sqrt3
Extend one side of the triangle
29
Angles less than 90/between 90 and 180

17. 9-40-?
61
41
SAS SSS ASA SAA HL
Opposite angles formed when two lines cross

18. scalene triangle
3 unequal sides
At least 2 equal sides
17
The base may be equal - greater or less than any other side - the legs are equal - angle across base is the vertex angle (+><) - base angles are equal

19. area of triangle
15
SAS SSS ASA SAA HL
.5B*h
Angles less than 90/between 90 and 180

20. 30-60-90 right triangle
Get shorter leg first - shorter leg is half hyp - to find short leg given hyp - div by 2 - to find hyp given short leg - *2 - find short leg given hyp - div by sqrt3 - find long leg given short leg - *sqrt3
Equal
Line drawn from any angle of a triangle to the midpoint of the opposite side
15

21. 20-21-?
All equal sides
17
Less than 90
29

22. equilateral triangle
Two angles totalling 180
All equal sides
Line segment from a vertex perpendicular to the base
5

23. complementary angles
Line segment from a vertex perpendicular to the base
Less than 90
Two angles totalling 90
5

24. right angle
180
90
S^2*sqrt(3)/4
Two angles totalling 180

25. similar triangles
SAS SSS AAA
26
More than 180
Less than 90

26. area of equilateral triangle
41
SAS SSS ASA SAA HL
C2=a2+b2
S^2*sqrt(3)/4

27. pythagorean theorem
Less than 90
Extend one side of the triangle
41
C2=a2+b2

28. 11-60-?
61
The base may be equal - greater or less than any other side - the legs are equal - angle across base is the vertex angle (+><) - base angles are equal
At least 2 equal sides
Less than 90

29. 8-15-?
All equal sides
17
3 unequal sides
Two angles totalling 90

30. reflex angle
Equal
More than 180
17
25

31. 2 facts about triangles
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
Extend one side of the triangle
Two angles totalling 90
A line that bisects (halves) an angle in a triangle

32. supplementary angles
Extend one side of the triangle
Two angles totalling 180
Less than 90
SAS SSS AAA

33. congruent angles
Less than 90
29
13
Equal

34. altitute/height
15
3 unequal sides
Line segment from a vertex perpendicular to the base
25

35. 10-24-?
180
Two angles totalling 90
26
A line that bisects (halves) an angle in a triangle

36. 9-12-?
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
5
15
Equal

37. angle bisector
SAS SSS AAA
180
A line that bisects (halves) an angle in a triangle
20