1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Dvinal [7]
3 years ago
5

An equilateral triangle has an altitude of 15 m. What is the perimeter of the triangle?

Mathematics
2 answers:
Brut [27]3 years ago
8 0

we know that

In the equilateral triangle every sides and angles are equal 

so

the measure of internal angles is equal to 60 degrees 

see the attached picture to better understand the problem

In the right triangle ABC

sin 60=BC/AB

where

BC is the altitude (opposite side angle 60 degrees

AB is the hypotenuse

Clear AB

AB=BC/sin 60\\ AB=15/(\frac{\sqrt{3}}{2}  )\\ AB=30/\sqrt{3}m

Perimeter of the triangle is equal to

P=AB+BD+AD

but remember that

AB=BD=AD

so

P=3*AB\\ P=3*\frac{30}{\sqrt{3}}  \\ \\ P=\frac{90}{\sqrt{3}}  \\ \\ P=30\sqrt{3} m

therefore

the answer is

30\sqrt{3} m


kondor19780726 [428]3 years ago
3 0
Equilateral triangle mean every sides and angles are equal 
so the measure of angles is 60 degrees 
 given that has an altitude of 15 m so this mean that 

sin 60 = altitude / hypotenuse 

sqrt3 /2 = 15/hyp.

hyp. = 15/(sqrt3 /2)

hyp. = 30/sqrt3 = 30sqrt3 / 3 = 10sqrt3

so in this way ve got that a side length is equal 10sqrt3 and the perimeter 

P = 3*10sqrt3 

P = 30sqrt3 m  so the 3rd choice is right,correct sure 

hope helped 


You might be interested in
Two trains travel a 160 km track each day. The express travels 10 km h^-1 faster and take 30 minutes less time than the normal t
aniked [119]
Let s = the speed of the slower train in km/hrs+10 = the speed of the faster train in km/hrLet t = time in hrs for the slower train to go 160 kmt-5 = time in hrs for faster train to go 160 km---------------Slower train:(1)
160=s.t

Faster train:(2) 160=(s+10) .(t-.5)From (1)(1) t=160/s
use the relations given in following screenshot and then use quadratic equation.

4 0
4 years ago
Amber's bank statement shows a closing balance of $224.13. There are no outstanding checks deposits. Her checkbook shows a balan
Lina20 [59]
Interest earned in the amount of $2.75
4 0
3 years ago
Read 2 more answers
By how many is 450 x 1000 less than 500,000
kompoz [17]
It is 50,000 less 

450 x 100 = 450,000 
3 0
3 years ago
Read 2 more answers
Help worth a lot of pounts
Anton [14]

Answer:

See below.

Step-by-step explanation:

Let x = amount of money you have in your account.

The money in your account plus the $125 extra that you need equals the total cost of the computer.

The equation is:

x + 125 = 2250

Now we solve the equation by subtracting 125 from both sides.

x = 2125

Answer: You have now $2125 in your account

7 0
3 years ago
Read 2 more answers
A point is an exact location that has no size or dimension. True or False?
Zarrin [17]
It's true because a pint is used to locate co-ordinates and has no size or dimension
5 0
3 years ago
Read 2 more answers
Other questions:
  • How do I solve this problem
    11·2 answers
  • Evan ran 9 and 3/5 miles in one hour and twenty four minutes. Find the average of minutes it took him to complete one mile.
    9·1 answer
  • What is a unit rate math
    10·1 answer
  • Solve the system of equations y=3x+2 y=x2-4x+2​
    14·1 answer
  • Which name accurately describes the figure shown below and why? A 4-sided figure with 2 parallel sides, 2 right angles, and 2 no
    9·2 answers
  • What is the best way to description X times Y in a sentence?
    14·1 answer
  • Write the expression in complete factored form.<br> x2(a + 5) + (a + 5) =
    10·1 answer
  • Please help asap I need this
    9·1 answer
  • Solve each equation mentally 1/7 × x = 1
    12·1 answer
  • 17. Which of the following transformations does NOT preserve congruence?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!