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Hi could someone please help me with this question I genuinely don't understand 🥲
Reply 1
Original post by N1c0l3z
Hi could someone please help me with this question I genuinely don't understand 🥲

image.jpg There's the question!
Original post by N1c0l3z
image.jpg There's the question!

To find…

Width of rectangle BD:
Use tan = opposite/adjecent to get BD
Which means…
Tan(60) = BD/7
7√3 = BD

Height of rectangle BF:
Since the two triangles are similar (due to the fact we know there’s a rectangle between them), we can use the similar triangle method to get BF.
Which means…
If BD -> AF is by dividing by (7√3)/6
Therefore CD -> BF is 7 divided by (7√3)/6 as well
Therefore BF = 2√3

Perimeter of BDEF:
Basically BF + FE + ED + DB
Which is…
2√3 + 2√3 + 7√3 + 7√3
= 18√3 cm

Area of BDEF:
Basically BF x BD
Which is…
2√3 x 7√3
= 42 cm^2

I hope this helps! I haven’t double checked my answer so I’m not fully sure if this is correct, but I know the method is definitely correct. :smile:
Reply 3
Original post by jelllyfiiish
To find…
Width of rectangle BD:
Use tan = opposite/adjecent to get BD
Which means…
Tan(60) = BD/7
7√3 = BD
Height of rectangle BF:
Since the two triangles are similar (due to the fact we know there’s a rectangle between them), we can use the similar triangle method to get BF.
Which means…
If BD -> AF is by dividing by (7√3)/6
Therefore CD -> BF is 7 divided by (7√3)/6 as well
Therefore BF = 2√3
Perimeter of BDEF:
Basically BF + FE + ED + DB
Which is…
2√3 + 2√3 + 7√3 + 7√3
= 18√3 cm
Area of BDEF:
Basically BF x BD
Which is…
2√3 x 7√3
= 42 cm^2
I hope this helps! I haven’t double checked my answer so I’m not fully sure if this is correct, but I know the method is definitely correct. :smile:

Omg thank you so much ! It was right 🙂 , also to find AF why did you divide by 6? Tysmmmm
Original post by N1c0l3z
Omg thank you so much ! It was right 🙂 , also to find AF why did you divide by 6? Tysmmmm
Triangle ABF and BCD are similar triangles - this concept is widely explored online (e.g. YouTube)!
You can also use ratios to help you solve this problem.

AF : BD
6 : 7√3
Is also equal to…
1 : (7√3)/6

Hope this diagram of ratios makes this look clearer. :smile:

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