A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 4 years ago

Find the area of the equilateral triangle with sides 10 cm.. Ans is supposed to 43.3cm^2 (according to the answer sheet) but no workings are given :(

  • This Question is Closed
  1. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ar of equilateral triangle=root3/4a^2

  2. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    First, divide in one of his heights the triangle into two triangles with a right angle (90, 60, 30 will be their angles). Then, you have 10 cm of hypothenuse, and 5 of base. You want to know the height. 10^2=height^2-5^2 75=height^2 sqrt(75)=height Then height*5/2 *2 (because you have 2 triangles) height*5=sqrt(75)*5=25*(sqrt(3))=43.3012~ cm2

  3. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1328412719708:dw| x^2+25=100 x=5(3)^1/2 Area=1/2*10*5(3)^1/2 =25(3)^1/2/2 =43.301cm^2

  4. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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
  • 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.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.