A triangular pyramid has a base shaped like an equilateral triangle. The legs of the equilateral triangle are all 20 inches long, and the height of the equilateral triangle is 17.3 inches. The pyramid's slant height is 13 inches. What is its surface area?

Surface area of pyramid with base equilateral triangle is square inches

Step-by-step explanation:

Recall the following result:

The total surface area(S) of a regular pyramid is given by,

                                      ...... (1)

Here, p represents the perimeter of the base , the slant height and B the base area of the pyramid.

From the given information:

Side of equilateral triangle = 20 inches

Slant height of the pyramid() = 13 inches.

First find the perimeter and Area of the base pyramid.

Perimeter of equilateral triangle(p) =

                                                          =

Area of equilateral triangle(B) =

                                                 =  square inches.

Substitute the above values in equation (1) as shown below:

square inches

Hence, the surface area of pyramid with base equilateral triangle is square inches.

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl