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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. acute/obtuse triangle
Less than 90
SAS SSS AAA
90
Angles less than 90/between 90 and 180

2. altitute/height
Line segment from a vertex perpendicular to the base
61
SAS SSS AAA
Opposite angles formed when two lines cross

3. reflex angle
8
More than 90 but less than 180
3 unequal sides
More than 180

4. obtuse angle
More than 90 but less than 180
Opposite angles formed when two lines cross
Angles less than 90/between 90 and 180
Equal

5. 7-24-?
Two angles totalling 180
20
61
25

6. complementary angles
Two angles totalling 90
At least 2 equal sides
5
Line drawn from any angle of a triangle to the midpoint of the opposite side

7. angle bisector
A line that bisects (halves) an angle in a triangle
All equal sides
Equal
61

8. 9-12-?
Two angles totalling 180
Opposite angles formed when two lines cross
180
15

9. straight angle
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
13
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
180

10. 2 facts about triangles
S^2*sqrt(3)/4
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
61
26

11. 10-24-?
20
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
26
180

12. 6-8-?
8
17
Line segment from a vertex perpendicular to the base
A line that bisects (halves) an angle in a triangle

13. median
Line drawn from any angle of a triangle to the midpoint of the opposite side
8
17
29

14. acute angle
41
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
More than 180
Less than 90

15. congruent triangles
SAS SSS ASA SAA HL
At least 2 equal sides
Line drawn from any angle of a triangle to the midpoint of the opposite side
Two angles totalling 90

16. 5-12-?
13
More than 180
5
Less than 90

17. 30-60-90 right triangle
180
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
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
13

18. 8-15-?
5
More than 180
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
17

19. 12-16-?
Extend one side of the triangle
All equal sides
5
20

20. supplementary angles
SAS SSS AAA
.5B*h
90
Two angles totalling 180

21. area of equilateral triangle
Less than 90
8
SAS SSS ASA SAA HL
S^2*sqrt(3)/4

22. vertical angles
Two angles totalling 180
Extend one side of the triangle
SAS SSS AAA
Opposite angles formed when two lines cross

23. pythagorean theorem
Extend one side of the triangle
C2=a2+b2
3 unequal sides
61

24. 15-20-?
25
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
SAS SSS ASA SAA HL
Line drawn from any angle of a triangle to the midpoint of the opposite side

25. Following is true about isosceles triangles
41
26
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
More than 180

26. similar triangles
90
SAS SSS AAA
Less than 90
S^2*sqrt(3)/4

27. isosceles triangle
More than 90 but less than 180
5
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
At least 2 equal sides

28. area of triangle
.5B*h
20
Two angles totalling 180
At least 2 equal sides

29. exterior angle
5
Extend one side of the triangle
Line segment from a vertex perpendicular to the base
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

30. 9-40-?
8
17
41
90

31. 3-4-?
5
SAS SSS AAA
41
.5B*h

32. equilateral triangle
5
C2=a2+b2
Two angles totalling 180
All equal sides

33. right angle
180
90
13
SAS SSS ASA SAA HL

34. congruent angles
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
Angles less than 90/between 90 and 180
Equal
More than 180

35. 20-21-?
29
90
SAS SSS AAA
Less than 90

36. 11-60-?
8
61
20
All equal sides

37. scalene triangle
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
Less than 90
Two angles totalling 180
3 unequal sides