Answer:
Use area of trap formula and special right triangles
Step-by-step explanation:
A = (.5)(10 + 18)(5)
Answer:
C
Step-by-step explanation:
Look at the angle markings. Angle C has one mark, Angles E and S have two marks, and Angles D and R have three marks.
Therefore, these angles correspond with one another and determine the order of the letters.
Answer:
See below.
Step-by-step explanation:
a.
The first figure has 1 square. The second figure has a column of 2 squares added to the left. The third figure has a column of 3 squares added to the left. Each new figure has a column of squares added to the left containing the same number of squares as the number of the figure.
b.
Figure 10 has 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55 squares.
c.
The formula for adding n positive integers starting at 1 is:
1 + 2 + 3 + ... + n = n(n + 1)/2
For figure 55, n = 55.
n(n + 1)/2 = 55(56)/2 = 1540
d.
Let's use the formula set equal to 190 and solve for n. If n is an integer, then we can.
n(n + 1)/2 = 190
n(n + 1) = 380
We know that 380 = 19 * 20, so n = 19.
Answer: yes
e.
Use the formula above,
S = n(n + 1)/2, where S is the sum.
f.
n(n + 1) = 1478
38 * 39 = 1482
37 * 38 = 1406
Answer:
12a. 471.2 cm²
12b. 60 m²
Step-by-step explanation:
Part A.
The surface area of each figure is the sum of the end area and the lateral area.
<u>cylinder</u>
S = (2)(πr²) +2πrh = 2πr(r +h)
S = 2π(5 cm)(5 cm +10 cm) =150π cm² ≈ 471.2 cm²
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<u>triangular prism</u>
S = (2)(1/2)bh + PL . . . . b=triangle base; h=triangle height; P=triangle perimeter; L=length of prism
S = (4 m)(1.5 m) + ((4 + 2·2.5) m)(6 m) = (6 + 54) m² = 60 m²
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Part B.
Surface area is useful in the real world wherever products are made from sheets of material or wherever coverings are applied.
Carpeting or other flooring, paint, wallpaper are all priced in terms of the area they cover, for example.
The amount of material used to make containers in the shapes shown will depend on the area of these containers (and any material required for seams).
