SOLUTION: Equilateral triangle △ABC has side length 2, M is the midpoint of segment AC, and C is the midpoint of BD. What is the area of △CDM? (please check the link below as it conta

Algebra ->  Triangles -> SOLUTION: Equilateral triangle △ABC has side length 2, M is the midpoint of segment AC, and C is the midpoint of BD. What is the area of △CDM? (please check the link below as it conta      Log On


   



Question 1151273: Equilateral triangle △ABC has side length 2, M is the midpoint of
segment AC, and C is the midpoint of BD. What is the area of
△CDM?
(please check the link below as it contains the image for the question)
https://i.imgur.com/g3InsY0.png

Found 2 solutions by ikleyn, jim_thompson5910:
Answer by ikleyn(53751) About Me  (Show Source):
You can put this solution on YOUR website!
.

HINT 1.  The area of the equilateral triangle is  a%5E2%2A%28sqrt%283%29%2F4%29 square units, where "a" is its side length.

         So, in this case, the area of the equilateral triangle ABC is  2%5E2%2A%28sqrt%283%29%2F4%29 = sqrt%283%29.



HINT 2.  The area of the triangle CDM is half the area of the triangle ABC.


Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Let's explore hint #2 that the tutor @ikleyn has provided.

Triangle ABC has base of BC = 2
Let h be the height of triangle ABC. It does not matter what h is for this thought experiment.
The area of triangle ABC is therefore, A = (1/2)*base*height = (1/2)*2*h = h.
Area of triangle ABC = h.

The base of triangle CDM is also 2, because C is the midpoint of BD, so BC = CD = 2.
The height of point M is half that of point A's height. Imagine that point A is (0, h). Through use of the midpoint formula, you'll find that the y coordinate of point M will be y = h/2.
So the height of triangle CDM is h/2.

area of triangle CDM = (1/2)*base*height
area of triangle CDM = (1/2)*2*(h/2)
area of triangle CDM = h/2
area of triangle CDM = (area of triangle ABC)/2