13,because it’s the single number that divides with 52
52:13=4
Answer:
CD = 14 cm; DE = 21 cm
Step-by-step explanation:
The perimeter is the sum of side lengths (in centimeters), so ...
CD + DE + CF + EF = 55
CD + DE + 8 + 12 = 55 . . . . . . . substittute for CF and EF
CD + DE = 35 . . . . . . . . . . . . . . subtract 20
___
The segment DF is a diagonal of the rhombus, so bisects angle D. That angle bisector divides ΔCDE into segments that are proportional. That is, ...
CD/DE = CF/EF = 8/12 = 2/3
___
So, we have two segments whose sum is 35 (cm) and whose ratio is 2 : 3. The total of "ratio units is 2+3=5, so each must stand for a length unit of 35/5 = 7 (cm). The sides are ...
CD = 2·7 cm = 14 cm
DE = 3·7 cm = 21 cm
<em>Check</em>
CD + DE = (14 +21) cm = 35 cm . . . . . matches requirements
Answer: Choice B
A net is shown with a pentagon in the middle and 5 identical triangles on the 5 sides of the pentagon
The pentagon forms the base of the pentagonal pyramid. Each lateral side is a triangle that meets at the very top of the pyramid. The base stays on the floor while the sides are folded up.
---------------------------
There are other possible net configurations to form a pentagonal pyramid, but the other answer choices do not make a pentagonal pyramid.
- Choice A produces a square pyramid.
- Choice C makes a triangular pyramid (aka tetrahedron).
- Choice D makes a hexagonal pyramid.
So we can rule choices A, C and D out.
Answer:
length = 36 ft; width = 12 ft
Step-by-step explanation:
Let the width be x.
The length is 3x.
The perimeter is the sum of two lengths and two widths, and it equals 96 ft.
3x + 3x + x + x = 96
8x = 96
x = 12
Width = x = 12 ft
Length = 3x = 3(12 ft) = 36 ft
