Magoosh
In the figure, ABCD is a square, and all the dots are evenly spaced: each vertical or horizontal distance between two adjacent dots is 3 units. Find the area of the shaded region.
A. 60
B. 72
C. 81
D. 96
E. 120
OA B.
In the figure, ABCD is a square, and all the dots are
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- Brent@GMATPrepNow
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If the vertical or horizontal distance between two adjacent dots is 3 units, then the square has dimensions 12 by 12
So, the area of the ENTIRE SQUARE = (12)(12) = 144
Now, notice that the square is comprised of 32 identical triangles
Since 16 of the triangles are shaded, the shaded regions represent 16/32 (aka 1/2) of the ENTIRE SQUARE
In other words, the area of the shaded region = 1/2 of 144
= 72
Answer: B
Cheers,
Brent
- fskilnik@GMATH
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Hi, Brent!
Your solution is beautiful, mathematically and graphically speaking!
Got a well-deserved "+1 upvote post" from me!
Regards
fskilnik.
Your solution is beautiful, mathematically and graphically speaking!
Got a well-deserved "+1 upvote post" from me!
Regards
fskilnik.
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
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English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770