ABC and BDE are two equilateral triangles such that D is mid-point of ...
ABC and BDE are two equilateral triangles such that D is mid-point of ...
To find the ratio of the areas of triangles ABC and BDE, we need to compare their areas.
Given:
- ABC and BDE are equilateral triangles.
- D is the midpoint of BC.
Let's start by finding the relationship between the sides of the two triangles.
1. Relationship between the sides:
- In an equilateral triangle, all sides are equal.
- Therefore, AB = BC = CA and BD = DE = EB.
Now, let's calculate the ratio of the areas of the two triangles.
2. Area of triangle ABC:
- The area of an equilateral triangle can be found using the formula: (sqrt(3)/4) * side^2.
- Let's assume the side length of ABC is 's'.
- Therefore, the area of ABC = (sqrt(3)/4) * s^2.
3. Area of triangle BDE:
- Since BD = DE = EB, triangle BDE is also an equilateral triangle.
- Let's assume the side length of BDE is 'x'.
- Therefore, the area of BDE = (sqrt(3)/4) * x^2.
4. Relationship between the side lengths:
- From step 1, we know that AB = BC = CA and BD = DE = EB.
- Since D is the midpoint of BC, we can conclude that BD = DC.
- Therefore, BD + DC = BC.
- Substituting the values, we get x + x = s.
- Simplifying, we have 2x = s.
- So, x = s/2.
5. Substituting the values in the area formulas:
- Area of ABC = (sqrt(3)/4) * s^2 = (sqrt(3)/4) * (2x)^2 = (sqrt(3)/4) * 4x^2 = sqrt(3) * x^2.
- Area of BDE = (sqrt(3)/4) * x^2.
6. Finding the ratio:
- Ratio of the areas = (Area of ABC) : (Area of BDE)
= (sqrt(3) * x^2) : ((sqrt(3)/4) * x^2)
= (sqrt(3) * x^2) / ((sqrt(3)/4) * x^2)
= (sqrt(3) * x^2) * (4/sqrt(3) * x^2)
= 4/1
= 4 : 1.
Therefore, the correct answer is option 'D', which states that the ratio of the areas of triangles ABC and BDE is 4 : 1.
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