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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 angle
SAS SSS ASA SAA HL
8
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

2. angle bisector
A line that bisects (halves) an angle in a triangle
17
5
Line segment from a vertex perpendicular to the base

3. 2 facts about triangles
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
More than 90 but less than 180
Two angles totalling 180

4. reflex angle
15
.5B*h
More than 180
SAS SSS AAA

5. isosceles triangle
Less than 90
26
5
At least 2 equal sides

6. Following is true about isosceles triangles
Line drawn from any angle of a triangle to the midpoint of the opposite side
5
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

7. equilateral triangle
90
All equal sides
Extend one side of the triangle
Line segment from a vertex perpendicular to the base

8. vertical angles
Two angles totalling 180
Opposite angles formed when two lines cross
SAS SSS ASA SAA HL
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. exterior angle
Extend one side of the triangle
180
8
C2=a2+b2

10. obtuse 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
More than 90 but less 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
At least 2 equal sides

11. similar triangles
.5B*h
15
25
SAS SSS AAA

12. 9-12-?
15
20
All equal sides
Extend one side of the triangle

13. acute/obtuse triangle
Angles less than 90/between 90 and 180
S^2*sqrt(3)/4
15
Line segment from a vertex perpendicular to the base

14. pythagorean theorem
SAS SSS ASA SAA HL
15
More than 180
C2=a2+b2

15. 30-60-90 right triangle
Extend one side of the 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
20
180

16. 6-8-?
90
26
8
Two angles totalling 180

17. 11-60-?
Two angles totalling 90
3 unequal sides
61
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

18. scalene triangle
3 unequal sides
Two angles totalling 90
Angles less than 90/between 90 and 180
A line that bisects (halves) an angle in a triangle

19. complementary angles
Line drawn from any angle of a triangle to the midpoint of the opposite side
Two angles totalling 90
8
SAS SSS AAA

20. 12-16-?
SAS SSS ASA SAA HL
15
20
.5B*h

21. area of equilateral triangle
Extend one side of the triangle
Line drawn from any angle of a triangle to the midpoint of the opposite side
S^2*sqrt(3)/4
41

22. 9-40-?
25
41
A line that bisects (halves) an angle in a triangle
S^2*sqrt(3)/4

23. altitute/height
Extend one side of the triangle
180
Line segment from a vertex perpendicular to the base
20

24. median
Equal
3 unequal sides
Line drawn from any angle of a triangle to the midpoint of the opposite side
13

25. congruent triangles
Opposite angles formed when two lines cross
.5B*h
180
SAS SSS ASA SAA HL

26. congruent angles
25
5
Equal
90

27. 15-20-?
25
Less than 90
Line drawn from any angle of a triangle to the midpoint of the opposite side
20

28. 10-24-?
61
90
At least 2 equal sides
26

29. straight angle
At least 2 equal sides
17
25
180

30. area of 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
.5B*h
A line that bisects (halves) an angle in a triangle
Less than 90

31. 8-15-?
Extend one side of the triangle
17
Less than 90
Line drawn from any angle of a triangle to the midpoint of the opposite side

32. 20-21-?
29
SAS SSS ASA SAA HL
Angles less than 90/between 90 and 180
Two angles totalling 180

33. right angle
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
A line that bisects (halves) an angle in a triangle
90

34. 7-24-?
25
Two angles totalling 90
61
At least 2 equal sides

35. 3-4-?
Two angles totalling 180
Equal
5
8

36. supplementary angles
Two angles totalling 180
15
Opposite angles formed when two lines cross
.5B*h

37. 5-12-?
C2=a2+b2
20
13
All equal sides