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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. straight angle
Line segment from a vertex perpendicular to the base
180
Two angles totalling 180
13

2. 3-4-?
A line that bisects (halves) an angle in a triangle
More than 180
5
61

3. area of equilateral triangle
15
S^2*sqrt(3)/4
Extend one side of the triangle
20

4. congruent angles
Equal
Two angles totalling 180
26
At least 2 equal sides

5. 15-20-?
Two angles totalling 90
180
8
25

6. complementary angles
Two angles totalling 90
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
All equal sides

7. reflex angle
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 180
29
3 unequal sides

8. 7-24-?
At least 2 equal sides
All equal sides
90
25

9. 10-24-?
25
26
SAS SSS AAA
25

10. similar triangles
C2=a2+b2
S^2*sqrt(3)/4
29
SAS SSS AAA

11. obtuse angle
Two angles totalling 180
Less than 90
Opposite angles formed when two lines cross
More than 90 but less than 180

12. congruent triangles
180
A line that bisects (halves) an angle in a triangle
SAS SSS ASA SAA HL
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. altitute/height
At least 2 equal sides
Two angles totalling 90
Line segment from a vertex perpendicular to the base
Angles less than 90/between 90 and 180

14. 12-16-?
20
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
More than 90 but less than 180

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

16. 8-15-?
17
Line drawn from any angle of a triangle to the midpoint of the opposite side
26
.5B*h

17. Following is true about isosceles triangles
More than 180
.5B*h
Extend one side of the 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

18. scalene triangle
Less than 90
Equal
3 unequal sides
8

19. equilateral triangle
20
All equal sides
26
Line segment from a vertex perpendicular to the base

20. right angle
17
20
90
All equal sides

21. 9-12-?
15
Two angles totalling 180
Less than 90
Line drawn from any angle of a triangle to the midpoint of the opposite side

22. exterior angle
41
Extend one side of the triangle
SAS SSS ASA SAA HL
180

23. median
61
Line drawn from any angle of a triangle to the midpoint of the opposite side
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
5

24. isosceles triangle
More than 90 but less than 180
At least 2 equal sides
25
Less than 90

25. 2 facts about triangles
5
C2=a2+b2
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

26. 9-40-?
25
SAS SSS AAA
41
Angles less than 90/between 90 and 180

27. acute angle
Less than 90
Line drawn from any angle of a triangle to the midpoint of the opposite side
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
At least 2 equal sides

28. 6-8-?
41
.5B*h
8
90

29. area of triangle
5
.5B*h
Extend one side of the triangle
13

30. angle bisector
A line that bisects (halves) an angle in a triangle
SAS SSS ASA SAA HL
5
Two angles totalling 90

31. pythagorean theorem
C2=a2+b2
A line that bisects (halves) an angle in a triangle
.5B*h
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

32. 20-21-?
Opposite angles formed when two lines cross
C2=a2+b2
29
180

33. 11-60-?
Angles less than 90/between 90 and 180
Equal
3 unequal sides
61

34. vertical angles
Opposite angles formed when two lines cross
C2=a2+b2
15
SAS SSS ASA SAA HL

35. acute/obtuse triangle
.5B*h
Equal
SAS SSS ASA SAA HL
Angles less than 90/between 90 and 180

36. supplementary angles
Line drawn from any angle of a triangle to the midpoint of the opposite side
17
.5B*h
Two angles totalling 180

37. 5-12-?
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 180
90
13