<u>Given</u>:
The length of DE is 8 cm and the measure of ∠ADE is 60°.
We need to determine the surface area of the pyramid.
<u>Length of AD:</u>
The length of AD is given by


Length of AD = 8 cm
<u>Slant height:</u>
The slant height EF can be determined using the trigonometric ratio.
Thus, we have;




Thus, the slant height EF is 4√3
<u>Surface area of the square pyramid:</u>
The surface area of the square pyramid can be determined using the formula,

Substituting the values, we have;




The exact form of the area of the square pyramid is 
Substituting √3 = 1.732 in the above expression, we have;


Rounding off to one decimal place, we get;

Thus, the area of the square pyramid is 174.8 cm²
Answer:
Pendulum will swing by an angle 0.666π
Step-by-step explanation:
We have given arc = 
And length of the pendulum l = 150 cm
Length of the pendulum will be equal to radius of the pendulum so r = 150 cm
Arc is given by 
So 

So pendulum will swing by an angle 0.666π
Answer:
Slope=2/7
Step-by-step explanation:
Slope=rise/run

Check the picture below.
so to find the surface area of the triangular prism, we simply add the areas of each of the figures composing it, as you can see is really just 2 triangles an 3 rectangles.
![\bf \stackrel{\textit{\Large Areas}}{\stackrel{triangles}{2\left[ \cfrac{1}{2}(4)(3) \right]}+\stackrel{\textit{rectangles}}{(3\cdot 10)+(4\cdot 10)+(5\cdot 10)}}\implies 12+30+40+50\implies 132](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7B%5CLarge%20Areas%7D%7D%7B%5Cstackrel%7Btriangles%7D%7B2%5Cleft%5B%20%5Ccfrac%7B1%7D%7B2%7D%284%29%283%29%20%5Cright%5D%7D%2B%5Cstackrel%7B%5Ctextit%7Brectangles%7D%7D%7B%283%5Ccdot%2010%29%2B%284%5Ccdot%2010%29%2B%285%5Ccdot%2010%29%7D%7D%5Cimplies%2012%2B30%2B40%2B50%5Cimplies%20132)
now, to get the volume is simply the area of the triangular face times the length, well, we know the area of one of the triangles is 6, times 10 is just 6*10 = 60.