A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
Please help :(
In the figure below, triangle TED in rectangle TBCD is equilateral. If TB = 10, to the nearest hundredth, what is the length of ED?
anonymous
 3 years ago
Please help :( In the figure below, triangle TED in rectangle TBCD is equilateral. If TB = 10, to the nearest hundredth, what is the length of ED?

This Question is Closed

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0dw:1338703391644:dw

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1Are you familiar with any trig?

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1hmm then again, you said geometry, so let me think of a way to do it without trig

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0no no, you can use a bit of trig if it is simple :)

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1Step 1) Label the length of ED x. So TE = x and TD = x as well since we're dealing with an equilateral triangle dw:1338704023305:dw

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1Step 2) Cut TD in half. Label the midpoint of TD point F and draw the segment EF dw:1338704102241:dw

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1The length of TF and FD are x/2 since we've cut TD = x in half

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1FE = TB, so FE = 10

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1So we have the following dw:1338704182291:dw

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1Since we have the right triangle EFD, we can say EF^2 + FD^2 = ED^2 but we know that EF = 10, FD = x/2 and ED = x, so... 10^2 + (x/2)^2 = x^2 100 + x^2/4 = x^2 400 + x^2 = 4x^2 400 = 4x^2  x^2 400 = 3x^2 3x^2 = 400 x^2 = 400/3 x = sqrt(400/3) x = 20/sqrt(3) x = 20*sqrt(3)/3 So the exact length of ED is 20*sqrt(3)/3 units.

jim_thompson5910
 3 years ago
Best ResponseYou've already chosen the best response.1After that, use a calculator to get 20*sqrt(3)/3 = (20*1.73205)/3 = 34.641/3 = 11.547 Giving us that ED is approximately 11.547 units, which rounds to 11.55

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0thank you so much x) you really helped me x)
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.