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Réponse :
The volume of a pyramid is given by the formula 1/3*base*height.
Here, the base has an area of 6*4 = 24cm².
We then replace that into the formula :
Volume of the pyramid = 1/3*24*8 = 64cm³
The volume of the pyramid is 64cm³.
I don't know if there's a formula for the surface of a pyramid so I'll just add all of the surfaces :
The base has an area of 24cm² (said earlier).
There are 2 triangles with a base of 6cm.
To get their height, we use Pythagorean theorem (see attachment) :
h = √(8²+(4/2)²)
h = √68
h = 2√17
Their surface added is 2*1/2*6*2√(17) = 12√17cm²
Using the same method for the 2 triangles of base 4, we get :
h = √(8²+(6/2)²)
h = √73
The area of the added base-4 triangles is 2*1/2*4*√73 = 4√73cm².
Thus, the total area is (24 + 12√17 + 4√73)cm².
