Thank you for your post!
I will need to inquire with the editor for a solution. Would you mind responding with the ISBN of your book?
Have a nice evening!
Sir, thank you for you response.
ISBN # 978-1-118-53280-5
Timothy J. Smith
Thank you for this information!
Unfortunately, this first edition title is out of print so I won't be able to reach the editor for a solution. I'm sorry for any inconvenience!
If it helps, the new question 13 in the second edition (ISBN: 978-1-119-38240-9) is:
13. The preceding pyramid has a square base, a
height of 9 cm, and a volume of 432 cm^3. What
is the lateral area of the pyramid rounded to
the nearest whole number? (Lateral Area = ½Ps
where P is the base perimeter and s is the slant
(A) 108 cm^2
(B) 135 cm^2
(C) 260 cm^2
(D) 520 cm^2
(E) 2,808 cm^2
13. C. 260 cm2
This problem requires you to take what you know and use it to work your way to what you
The formula for the volume of a pyramid is 1/3Bh. The volume and height of the pyramid are
given, so you can put those values into the formula and solve for B, base area. This process
reveals that the base area is 144 cm^2.
The base is a square, so the sides have equal measures. The measure of a side times itself
gives the area of the square, so a side is equal to the square root of the area. The square root
of 144 is 12, so each side is 12 cm.
That means the distance from the center of the square base to the midpoint of one of its
sides is 6 cm. The center-midpoint segment, the segment representing the height of the
pyramid, and a segment representing the slant height of the pyramid form a right triangle.
By using the Pythagorean theorem, a^2 + b^2 = c^2, you can determine that the slant height of
the pyramid is approximately 10.8 cm.
With the information gathered so far, you have what you need to use the formula for the lateral
area of a pyramid, which is 1/2 times perimeter times slant height. By putting the known
values into the formula, you can conclude that the lateral area of the pyramid, to the nearest
whole number, is 260 cm^2.
Does this help?
Have a nice afternoon!