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The area of quadrilateral BCDE is the same as the area of...

Question 21b:
BC = 3cm
The area of quadrilateral BCDE is the same as the area of triangle ABE.
Find the length of AB correct to three significant figures.

Any help with this please?

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Reply 1

ghostwalker

Original post by JackLebeau66

Question 21b:
BC = 3cm
The area of quadrilateral BCDE is the same as the area of triangle ABE.
Find the length of AB correct to three significant figures.

Any help with this please?

Since the area of the quadrilateral is the same as the area of triangle ABE

Then the area of the triangle ACD is twice the area of the triangle ABE.

Since these are similiar triangles,

The lengths in the triangle ACD are

\sqrt{2}

times the corresponding lengths in the triangle ABE.

Can you finish from there?

Reply 2

123Usha

No, please show me how can find length of AB

Reply 3

have

Original post by 123Usha

No, please show me how can find length of AB

Perhaps form an equation with the information, setting x = AB, and then on both sides of the equation being the two ways you can write the length of AC in terms of x.

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