Answer:
x = 96.23 if x is the area of the base
x =21 if x is the side length of the base
Step-by-step explanation:
The volume of a square pyramid is given by
V=1/3 a^ 2 h
We know the volume is 441 and the area of the base is a^2 which is x
and the height is 1/7x
Substituting these values in
441 = 1/3 (x) 1/7x
441 =1/21 x^2
Multiply each side by 21
441*21 = 21*1/21 x^2
9261 = x^2
Take the square root of each side
sqrt(9261) = sqrt(x^2)
x = 96.23
I am thinking you mean x is the side length on the base
We know the volume is 441 and the area of the base is a^2 which is x^2
and the height is 1/7x
Substituting these values in
441 = 1/3 (x^2) 1/7x
441 =1/21 x^3
Multiply each side by 21
441*21 = 21*1/21 x^3
9261 = x^3
Take the cube root of each side
(9261) ^ (1/3) = (x^3)^(1/3)
21 =x
Answer:
D
Step-by-step explanation:
We name the corners of the triangle as the attached image.
As we can see, triangle ABC is a right-angled triangle with Angle B equal to 90 degree.
As ABC is a right triangle, so that total measures of angle A and angle C is 90 degree
=> m∠A + m∠C = 90
=> m∠A + 45 = 90
=> m∠A = 90 - 45 = 45
=> m∠A = m∠C
So that ABC is also an isosceles triangle.
=> AB = AC = x
As ABC is a right triangle, according to Pythagoras theorem, we have the following equation:
AB^2 + BC^2 = AC^2
=> x^2 + x^2 = 20^2
=> 2.x^2 = 400
=> x^2 = 400/2 = 200
=> x = ≈ 14.14
So that x ≈ 14.14, the correct answer is D
I think it was for 2.33 cents??
80/1hour for 3/4 hours= 80*3=240/4=60
55/1hour=55+(55/5)=55+11=66
60+66=126km
126km