Asked by cody

The length of the hypotenuse of a 30, 60, 90 triangle is 7 how do you find perimeter?
Answered by MathMate
The ratios of the sides of the 30-60-90 triangle are:
1 : √3 : 2
So the ratio of the perimeter to the hypotenuse is
3+√3 : 2
Use cross-product to find:
perimeter / 7 = (3+√3) / 2
Answered by cody
Sorry, but I still don't get it
Answered by MathMate
Fact: all 30-60-90 triangles are similar.
Fact: therefore the ratio of the perimeter to the hypotenuse is the same for all 30-60-90 triangles.

We have arbitrarily created a 30-60-90 triangle with hypotenuse = 2.

So to get a triangle with a hypotenuse of 7, we need to multiply everything by 7/2=3.5.
The sides of the given triangle is therefore (1,√3,2)×3.5, or
(3.5, 3.5√3, 7)
Add up the three numbers (lengths of sides) to get the perimeter.
Answered by cody
I guess I'm lost my answer choices are;
7/2+21/2sqrt3
21+7sqrt3
7+21sqrt3
21/2+7/2sqrt3
So I don't understand
Answered by MathMate
Did you add the three sides, 3.5, 3.5√3 and 7?
Remember that 3.5 is the same as 7/2, and so on.
Answered by lilman
That's the problem I don't know how to add them, I'm assuming It would be 21+7sqrt3
Answered by MathMate
It's almost good. You probably just forgot to divide by the common denominator 2.
The answer should therefore be
(21+7sqrt(3))/2
=21/2 + (7/2)sqrt(3)
Answered by lilman
I did thanks for reminding me
Answered by Aiko ♡
GEOM B U9 L2 Semester Exam

1. D, 15° and 75°

2. B, 40

3. B, 10

4. B, 52 ft.

5. B, DGH ~ DFE; SAS ~

6. A, AA Postulate

7. A, 24

8. C, 6√2 miles; 6√11 miles

9. A, x = 10

10. B, no

11. C, obtuse

12. C, 17√2 ft

13. D, 21/2 + 7/2√3

14. D, 86.19°

15. C, sin A = 21/29, cos A = 20/29

16. B, 2.1 mi

17. A, about 29 miles at 25° south of west

18. C

19. B, P'(-8, -1), Q'(-6, 8), R'(4, 3)

20. D, 288°

21. D, 2

22. B, X

23. B, enlargement; 2

24. B, glide reflection; translate 8 units to the right then reflect across the line y = 4

25. C, 812 in²

26. B, 25,7 ft

27. A, 70cm²

28. 40.8 ft²

29. A, 585 in²

30. A, 8,000

31. B, 40π in.

32. C, 45π m

33. D, 4.2025π m²

34. B, 51.8 in.²

35. A, 30

36. A, 472 m²; 486 m²

37. B, 308π in.²

38. C, 57 ft²

39. A, 1,802 m²

40. B, 1:4

41. B, 1,472.6 in.³

42. A, 143.2 ft²

43. C, 1,344.8 m²

44. D, 7:18

45. C, 68

46. B, 60

47. C, 47°

48. A, 44°

49. A, 34°

50. A, (x + 3)² + (y - 2)² = 9

51. C, (x - 2)² + (y + 5)² = 241

52. C, 6:5

53. C, 2/91
Answered by Sawako
@aiko are you sure these are right? i dont want to fail i solved half of them on my own to be safe...
Answered by Sawako
plus when i first took it i left since id didn't finish and when i came back the question had different numbers before it was 5.2 then it became 4,7 w/ different answer choice...
Answered by Huh
Does anyone have all the correct answers because the guy above has a handful of correct ones?
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