Areas of Parallelograms and Triangles

In summary, the problem involves two equilateral triangles, ABC and BDE, with D being the midpoint of BC. If AE intersects BC at F, the following relationships can be shown: (i) the area of BDE is one-fourth the area of ABC, (ii) the area of BDE is half the area of BAE, (iii) the area of ABC is twice the area of BEC, (iv) the area of BFE is equal to the area of AFD, (v) the area of BFE is twice the area of FED, and (vi) the area of FED is half the area of AFC. To solve the problem, one can use the formula for the area of an
  • #1
agnibho
46
0

Homework Statement


ABC and BDE are two equilateral triangles such that D is the midpoint of BC. If AE intersects BC at F, show that :-
(i) ar(BDE) = 1/4 ar(ABC)
(ii) ar(BDE) = 1/2 ar(BAE)
(iii) ar(ABC) = 2ar(BEC)
(iv) ar(BFE) = ar(AFD)
(v) ar(BFE) = 2ar(FED)
(vi) ar(FED) = 1/2ar(AFC)


Homework Equations





The Attempt at a Solution


There was this hint :- [join EC and AD and then showing BE ll AC and DE ll AB,etc.]
 
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  • #2
I couldn't upload the diagram.
I tried to follow the hint but from there on I couldn't succeed in solving this sum.
If anyone would tell me how to do this sum I'll be pleased
 
  • #3
agnibho said:
ABC and BDE are two equilateral triangles such that D is the midpoint of BC. If AE intersects BC at F, show that :-
(i) ar(BDE) = 1/4 ar(ABC)
(ii) ar(BDE) = 1/2 ar(BAE)
(iii) ar(ABC) = 2ar(BEC)
(iv) ar(BFE) = ar(AFD)
(v) ar(BFE) = 2ar(FED)
(vi) ar(FED) = 1/2ar(AFC)

There was this hint :- [join EC and AD and then showing BE ll AC and DE ll AB,etc.]

My take on your diagram attached.
To continue, what is the formula for the area of an equilateral triangle?
 

Attachments

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  • #4
Area of an equilateral triangle = [tex]\sqrt{}3[/tex]/4*side2
 
  • #5
agnibho said:
Area of an equilateral triangle = [tex]\sqrt{}3[/tex]/4*side2

I assume my diagram was correct?

Anyway, D is at the midpoint of BC, so BD = BC/2
Aabc = [tex]\sqrt{}3[/tex]/4*BC2
Abde = [tex]\sqrt{}3[/tex]/4*BD2 = [tex]\sqrt{}3[/tex]/4*(BC/2)2

Finish that and retry the others.
 
  • #6
Yes your diagram was correct
 
  • #7
Thanks for your help.
 

Related to Areas of Parallelograms and Triangles

What is the formula for finding the area of a parallelogram?

The formula for finding the area of a parallelogram is base x height, where the base is the length of one of the sides and the height is the perpendicular distance between that side and its opposite side.

How is the area of a triangle different from the area of a parallelogram?

The area of a triangle is half the area of a parallelogram with the same base and height. This is because a triangle can be divided into two equal parts, each of which is a right triangle.

Can the area of a parallelogram or triangle be negative?

No, the area of a parallelogram or triangle cannot be negative. It represents a measure of space, which is always positive.

What is the difference between a base and a height in a parallelogram or triangle?

In a parallelogram, the base is one of the sides of the shape, while the height is the perpendicular distance between that side and its opposite side. In a triangle, the base is one of the sides of the shape, while the height is the perpendicular distance from the base to the opposite vertex.

How can the area of a parallelogram or triangle be used in real-world applications?

The area of a parallelogram or triangle can be used to calculate the amount of material needed for a given shape, such as for flooring or painting a wall. It can also be used in geometry and engineering to find the area of irregular shapes by breaking them down into parallelograms or triangles.

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