|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
09 Apr 2020, 07:38
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
69% (01:41) correct
31%
(01:37)
wrong
based on 72
sessions
History
Date
Time
Result
Not Attempted Yet
The base of a regular pyramid is a square and each of the other four sides is an equilateral triangle, length of each side being 20 cm. What is the height of the pyramid from the top vertex to the base?
A. 10√3
B. 10√2
C. 8√3
D. 12
E. 5√5
Are You Up For the Challenge: 700 Level Questions
A. 10√3
B. 10√2
C. 8√3
D. 12
E. 5√5
Are You Up For the Challenge: 700 Level Questions
09 Apr 2020, 07:53
Kudos
Bookmarks
Bunuel
Look at the attached figure..
Now ABC is an equilateral triangle.
The slanting height S of the pyramid is same as the altitude of ABC = \(20*\frac{\sqrt{3}}{2}=10\sqrt{3}\)
Now take right angled triangle whose sides are AO, S and base..Base = 20/2=10, S=10\(\sqrt{3}\),
so height =\(\sqrt{10^2*3-10^2}=\sqrt{200}=10\sqrt{2}\)
B
Attachments
squarepyramid.png [ 7.98 KiB | Viewed 3910 times ]
11 Apr 2020, 16:01
Kudos
Bookmarks
Square = all sides 20, middle at 1/2*20 = 10
Triangle = all sides 20 --> cut in half to find heights (30-60-90) 10:10sqrt(3):20
height from vertex = 10sqrt(3)^2 - 10^2 = 300-100 = 200
200 = x^2
x = 10sqrt(2)
B
Triangle = all sides 20 --> cut in half to find heights (30-60-90) 10:10sqrt(3):20
height from vertex = 10sqrt(3)^2 - 10^2 = 300-100 = 200
200 = x^2
x = 10sqrt(2)
B
