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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. reflex angle
13
Equal
Opposite angles formed when two lines cross
More than 180

2. 30-60-90 right triangle
SAS SSS AAA
25
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
All equal sides

3. 8-15-?
Less than 90
13
20
17

4. 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
25
5
17

5. 20-21-?
29
C2=a2+b2
Line segment from a vertex perpendicular to the base
61

6. 12-16-?
15
26
20
13

7. congruent triangles
.5B*h
SAS SSS ASA SAA HL
More than 180
13

8. area of equilateral triangle
S^2*sqrt(3)/4
Opposite angles formed when two lines cross
41
All equal sides

9. 9-40-?
3 unequal sides
A line that bisects (halves) an angle in a triangle
Line segment from a vertex perpendicular to the base
41

10. isosceles triangle
13
At least 2 equal sides
Line drawn from any angle of a triangle to the midpoint of the opposite side
5

11. exterior angle
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
Extend one side of the triangle
Less than 90

12. obtuse angle
More than 90 but less than 180
C2=a2+b2
All equal sides
More than 180

13. median
26
Line drawn from any angle of a triangle to the midpoint of the opposite side
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
13

14. 15-20-?
25
17
SAS SSS ASA SAA HL
Line drawn from any angle of a triangle to the midpoint of the opposite side

15. angle bisector
3 unequal sides
A line that bisects (halves) an angle in a triangle
S^2*sqrt(3)/4
61

16. pythagorean theorem
At least 2 equal sides
Line segment from a vertex perpendicular to the base
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
C2=a2+b2

17. 6-8-?
Line segment from a vertex perpendicular to the base
A line that bisects (halves) an angle in a triangle
8
180

18. congruent angles
180
More than 90 but less than 180
Equal
Two angles totalling 90

19. Following is true about isosceles triangles
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
25
3 unequal sides

20. supplementary angles
29
20
Two angles totalling 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

21. 9-12-?
15
8
C2=a2+b2
Extend one side of the triangle

22. equilateral triangle
61
29
All equal sides
Opposite angles formed when two lines cross

23. 10-24-?
26
SAS SSS AAA
8
61

24. 5-12-?
90
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
5

25. complementary angles
Two angles totalling 90
Equal
Less than 90
13

26. acute/obtuse triangle
25
Angles less than 90/between 90 and 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
SAS SSS ASA SAA HL

27. vertical angles
15
Opposite angles formed when two lines cross
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

28. scalene triangle
15
The sum of any two sides muse be greater than the 3rd side - the largest side lies opposite the largest angle and vice versa
3 unequal sides
More than 90 but less than 180

29. right angle
Extend one side of the triangle
90
5
SAS SSS ASA SAA HL

30. acute angle
25
Less than 90
41
29

31. altitute/height
Less than 90
Two angles totalling 180
Line segment from a vertex perpendicular to the base
17

32. 11-60-?
A line that bisects (halves) an angle in a triangle
29
61
180

33. straight angle
5
Less than 90
A line that bisects (halves) an angle in a triangle
180

34. similar triangles
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
Angles less than 90/between 90 and 180
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 AAA

35. 7-24-?
Two angles totalling 180
25
20
More than 180

36. area of 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
Two angles totalling 180
.5B*h
61

37. 3-4-?
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
41
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