120
72 cm square.
138.48
It depends on the dimensions of the base and the height (slant or vertical) of the pyramid.
The surface area is length times width plus length. Then you find the square root of the width divided by two and then squared. You add this to the height squared plus the width. The width is multiplied by the square root of 1/2 squared plus the height squared.
42.7
72 cm square.
138.48
It depends on the dimensions of the base and the height (slant or vertical) of the pyramid.
The surface area is length times width plus length. Then you find the square root of the width divided by two and then squared. You add this to the height squared plus the width. The width is multiplied by the square root of 1/2 squared plus the height squared.
Call the length of the base s and the slant height of one triangle l SA = s2 + 2sl
Surface area = 2*(length*width + width+height + height*length) = 370.125 square units.
You need some information about the height of the pyramid and the formula will depend on whether you have the vertical height or the slant height or the length of a lateral edge.
42.7
Volume = 960 cm3
The surface area of the pyramid is superfluous to calculating the slant height as the slant height is the height of the triangular side of the pyramid which can be worked out using Pythagoras on the side lengths of the equilateral triangle: side² = height² + (½side)² → height² = side² - ¼side² → height² = (1 - ¼)side² → height² = ¾side² → height = (√3)/2 side → slant height = (√3)/2 × 9cm = 4.5 × √3 cm ≈ 7.8 cm. ---------------------------- However, the surface area can be used as a check: 140.4 cm² ÷ (½ × 9 cm × 7.8 cm) = 140.4 cm² ÷ 35.1 cm² = 4 So the pyramid comprises 4 equilateral triangles - one for the base and 3 for the sides; it is a tetrahedron.
It is 9180900 square inches.
The height would be The square root of the square of the slant surface length minus the square of the radius of the cone at the base.