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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. area of triangle
.5B*h
25
41
A line that bisects (halves) an angle in a triangle

2. acute angle
Less than 90
3 unequal sides
8
Line segment from a vertex perpendicular to the base

3. pythagorean theorem
Less than 90
S^2*sqrt(3)/4
More than 90 but less than 180
C2=a2+b2

4. 5-12-?
13
Two angles totalling 90
Opposite angles formed when two lines cross
SAS SSS AAA

5. congruent angles
Equal
Line segment from a vertex perpendicular to the base
Two angles totalling 180
Angles less than 90/between 90 and 180

6. similar triangles
SAS SSS AAA
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
All equal sides
61

7. 11-60-?
61
25
S^2*sqrt(3)/4
Equal

8. right angle
25
90
All equal sides
29

9. 15-20-?
Equal
26
13
25

10. 30-60-90 right triangle
8
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
Two angles totalling 90
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

11. Following is true about isosceles triangles
Extend one side of the triangle
SAS SSS ASA SAA HL
More than 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

12. reflex angle
More than 180
Extend one side of the triangle
S^2*sqrt(3)/4
13

13. 7-24-?
Less than 90
Equal
13
25

14. vertical angles
Angles less than 90/between 90 and 180
At least 2 equal sides
Opposite angles formed when two lines cross
Less than 90

15. obtuse angle
41
Opposite angles formed when two lines cross
More than 90 but less than 180
25

16. exterior angle
Opposite angles formed when two lines cross
20
Extend one side of the triangle
A line that bisects (halves) an angle in a triangle

17. isosceles triangle
15
8
Opposite angles formed when two lines cross
At least 2 equal sides

18. congruent triangles
3 unequal sides
SAS SSS ASA SAA HL
Two angles totalling 90
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa

19. straight angle
Opposite angles formed when two lines cross
SAS SSS AAA
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

20. supplementary angles
S^2*sqrt(3)/4
Two angles totalling 180
180
SAS SSS ASA SAA HL

21. complementary angles
Equal
SAS SSS AAA
26
Two angles totalling 90

22. 3-4-?
Two angles totalling 90
Extend one side of the triangle
5
C2=a2+b2

23. area of equilateral triangle
SAS SSS AAA
S^2*sqrt(3)/4
29
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

24. 9-12-?
25
S^2*sqrt(3)/4
15
17

25. altitute/height
SAS SSS AAA
Equal
Extend one side of the triangle
Line segment from a vertex perpendicular to the base

26. 12-16-?
61
20
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

27. median
90
Two angles totalling 180
25
Line drawn from any angle of a triangle to the midpoint of the opposite side

28. scalene triangle
15
Two angles totalling 180
3 unequal sides
Extend one side of the triangle

29. equilateral 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
Angles less than 90/between 90 and 180
S^2*sqrt(3)/4
All equal sides

30. 8-15-?
S^2*sqrt(3)/4
17
Extend one side of the triangle
.5B*h

31. 20-21-?
26
Angles less than 90/between 90 and 180
29
All equal sides

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

33. 6-8-?
.5B*h
8
At least 2 equal sides
17

34. 10-24-?
More than 180
26
25
5

35. 2 facts about triangles
Line drawn from any angle of a triangle to the midpoint of the opposite side
Extend one side of the triangle
A line that bisects (halves) an angle in a triangle
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa

36. angle bisector
Two angles totalling 180
3 unequal sides
Line drawn from any angle of a triangle to the midpoint of the opposite side
A line that bisects (halves) an angle in a triangle

37. 9-40-?
15
3 unequal sides
41
Two angles totalling 90