Answers:
- a) 693 sq cm (approximate)
- b) 48 sq cm (exact)
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Explanation:
Part (a)
A regular triangular pyramid, aka regular tetrahedron, has all four triangles that are identical copies of one another. They are congruent triangles. This will apply to part (b) as well.
To find the area of one of the triangles, we'll use the formula
A = 0.25*sqrt(3)*x^2
where x is the side length. This formula applies to equilateral triangles only.
In this case, x = 20, so
A = 0.25*sqrt(3)*x^2
A = 0.25*sqrt(3)*20^2
A = 173.20508 approximately
That's the area of one triangle, but there are four total, so the entire area is about 4*173.20508 = 692.82032 which rounds to 693 sq cm.
The units "sq cm" can be written as "cm^2".
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Part (b)
We'll use the same idea as part (a). But the formula to find the area of one triangle is much simpler.
The area of one of the triangles is A = 0.5*base*height = 0.5*6*4 = 12 sq cm.
So the area of all four triangles combined is 4*12 = 48 sq cm
This area is exact.
The area of each 2D flat net corresponds exactly to the surface area of each 3D pyramid. This is because we can cut the figure out and fold along the lines to form the 3D shapes.
a)
Add the score and then square the sum.
By using the summation notation we can write the above statement is (Σx)²
b)
Square each score and then add the squared values.
By using the summation notation we can write the above statement is Σx²
Subtract 2 point from each score and then add the resulting values.
By using the summation notation we can write the above statement is Σ(x-2)
Subtract 1 point from each score and square the resulting values. Then add the squared values.
By using the summation notation we can write the above statement is Σ(x-1)²
Answer:
yeah
Step-by-step explanation:
ok so dimensions is like area the dimensions of a cubes side is a one by one or the base and height of a cube is 1 inch each get it now or do you need me to explain more?
Answer:
392π
Step-by-step explanation:
Equation is 1/3(piR^2)*h
Radius is 7, 7 squared is 49.
1/3(49π)(24)
392π
