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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. 8-15-?
More than 180
A line that bisects (halves) an angle in a triangle
At least 2 equal sides
17

2. acute/obtuse triangle
Angles less than 90/between 90 and 180
.5B*h
Two angles totalling 90
20

3. 12-16-?
Two angles totalling 180
20
90
3 unequal sides

4. 9-40-?
29
41
A line that bisects (halves) an angle in a triangle
All equal sides

5. 10-24-?
Opposite angles formed when two lines cross
.5B*h
26
More than 90 but less than 180

6. congruent angles
Equal
26
29
Extend one side of the triangle

7. congruent triangles
At least 2 equal sides
180
SAS SSS ASA SAA HL
Line segment from a vertex perpendicular to the base

8. vertical angles
Opposite angles formed when two lines cross
20
Two angles totalling 90
25

9. pythagorean theorem
Two angles totalling 90
.5B*h
C2=a2+b2
Angles less than 90/between 90 and 180

10. 20-21-?
C2=a2+b2
29
Equal
Opposite angles formed when two lines cross

11. reflex angle
Line segment from a vertex perpendicular to the base
More than 180
Less than 90
61

12. Following is true about isosceles 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
13
17
SAS SSS AAA

13. 9-12-?
A line that bisects (halves) an angle in a triangle
Extend one side of the triangle
Less than 90
15

14. scalene triangle
3 unequal sides
13
SAS SSS AAA
More than 180

15. acute angle
Less than 90
90
More than 180
Line segment from a vertex perpendicular to the base

16. right angle
SAS SSS ASA SAA HL
More than 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
90

17. similar triangles
Line drawn from any angle of a triangle to the midpoint of the opposite side
29
SAS SSS AAA
Less than 90

18. 6-8-?
Line segment from a vertex perpendicular to the base
8
C2=a2+b2
90

19. altitute/height
Line segment from a vertex perpendicular to the base
Equal
29
61

20. isosceles triangle
SAS SSS AAA
At least 2 equal sides
90
Extend one side of the triangle

21. straight angle
More than 180
180
90
All equal sides

22. 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
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
20

23. angle bisector
A line that bisects (halves) an angle in a triangle
Opposite angles formed when two lines cross
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

24. area of equilateral triangle
13
S^2*sqrt(3)/4
SAS SSS AAA
180

25. area of triangle
Line drawn from any angle of a triangle to the midpoint of the opposite side
S^2*sqrt(3)/4
.5B*h
25

26. 15-20-?
A line that bisects (halves) an angle in a triangle
29
25
S^2*sqrt(3)/4

27. 5-12-?
25
13
Opposite angles formed when two lines cross
More than 90 but less than 180

28. exterior angle
17
29
Extend one side of the triangle
5

29. 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
5
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 90 but less than 180

30. 7-24-?
SAS SSS ASA SAA HL
25
Less than 90
61

31. supplementary angles
Two angles totalling 180
41
26
5

32. obtuse angle
More than 90 but less than 180
S^2*sqrt(3)/4
Angles less than 90/between 90 and 180
Opposite angles formed when two lines cross

33. 11-60-?
61
At least 2 equal sides
Two angles totalling 180
Two angles totalling 90

34. median
29
Extend one side of the triangle
Line drawn from any angle of a triangle to the midpoint of the opposite side
25

35. 2 facts about triangles
SAS SSS AAA
Line drawn from any angle of a triangle to the midpoint of the opposite side
All equal sides
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. equilateral triangle
61
C2=a2+b2
All equal sides
SAS SSS AAA

37. complementary angles
All equal sides
15
SAS SSS ASA SAA HL
Two angles totalling 90