Answer:
72 mins
Step-by-step explanation:
24/4 = 6
So each poster take 6 mins to decorate
12 x 6 = 72
Octagon, stop sign.
Eight isoscles triangles. It looks like we're told the side is 9.9 and the height to the side (also called the apothem) is 12.
So each isosceles triangle has area (1/2)(9.9)(12) and we have eight of them,
area = 8(1/2)(9.9)(12) = 475.2
Answer: 475.2
Usually we wouldn't be told 9.9 -- this is the baby version. We know each of those isoscles triangles has unique angle 360/8=45 degrees, so the apothem and half the side of the octagon are a right triangle with acute angle 22.5 degrees.
The area of the right triangle with long leg 12, short leg x,
tan 22.5 = x/12 or
x = 12 tan 22.5
Twice that is what we're told is 9.9; let's check:
2x = 24 tan 22.5 = 9.941125496954282
The area of the little right triangle is
(1/2) 12 × 12 tan 22.5
and there are 16 of these
16 (1/2) 12 × 12 tan 22.5 ≈ 477.174
We are given with the sequence -20, -16, -12, -8. From this sequence, we can see that the arithmetic difference is +4, from -(-20 + 16). hence following the arithmetic formula of an = a1 + d *(n-1). Substituting, an = -20 + 4 *(n-1) where n is an integer
The area of a triangle can be calculated using the formula
1/2 (base) (height)
Let's substitute our known values, letting x represent the value of the height of the triangle.
16 = 1/2* x* 2x
Let's Simplify!
16 = x^2
Finally, lets take the square root of both sides, to get rid of the exponent on the right side of the equation.
x= positive OR negative 4.
However, because x is equal to the height, we know that it can't be negative, so we know that it is positive 4.
The height of the triangle = 4 inches
The base of the triangle = 2h = 8 inches