Hello :
cos60 = cos(-60)=0.5
Answer:
(4, 5 )
Step-by-step explanation:
x + y = 9 → (1)
x - y = - 1 → (2)
adding the 2 equations term by term will eliminate y
2x + 0 = 8
2x = 8 ( divide both sides by 2 )
x = 4
substitute x = 4 into either of the 2 equations and solve for y
substituting into (1)
4 + y = 9 ( subtract 4 from both sides )
y = 5
solution is (4, 5 )
You first divide the number by 100 and then multiply it by the percentage that you are given
We have a bunch of rectangles making up the lateral sides of this figure. They have side length 12 and height 13.
So the area of one rectangle is 12 x 13 = 156.
We have 6 of these rectangles, so our lateral area is 6(156) = 936.
The total surface area requires that we include the area of the base. To find the area of a regular polygon we take half of the product of the apothem and perimeter.
A = (1/2)*a*p
The apothem is given to be 10.39,
and the perimeter is fairly easy to calculate:
With the side length being 12, the perimeter is then 6(12) = 72.
So then the area of our base is (1/2)*10.39*72 = 374.04
So then the total surface area is the (base area) + (lateral area),
374.04 + 936 = 1310.04
