Answer:
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Step-by-step explanation:
Answer:
u can find the answer in calculate
Answer:
(2) angle1 = 139, angle2 = 41, angle4 = 41, angle5 = 139, angle6 = 41, angle7 = 139, angle8 = 41
(3) angle1 = 150, angle2 = 30, angle4 = 30, angle5 = 150, angle6 = 30, angle7 = 150, angle8 = 30
Step-by-step explanation:
All angle are either equal to each other or supplementary. I use corresponding angles and vertical angles to prove each of the above.
For number 3, angle 3 and angle 8 are supplementary, so they add up to 180:
8x +70 + (4x - 10) = 180
12x + 60 = 180
12x = 120
x = 10
So if x = 10, then 8x + 70 = 8(10) + 70 = 150
That means all angles are either 150 or 30 for number 3.
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
24 students forget their pencil out of 120 students.
