I'm trying so hard to understand this, but I am currently failing geometry just because of this unit. I tried looking up information, writing notes, everything. Hopefully someone can help me ASAP. Please and thank you for all your help.
1. The base of a regular pyramid is a hexagon.
What is the area of the base of the pyramid?
Enter your answer in the box. Express your answer in radical form.
____ cm2
------------------------------------------------------------------------------------------------------------------------------------------------------------
2. This image shows a square pyramid.
What is the surface area of this square pyramid?
25 ft²
100 ft²
125 ft²
200 ft²
------------------------------------------------------------------------------------------------------------------------------------------------------------
3.
What is the surface area of this square pyramid?
Round your answer to the nearest tenth, if necessary.
4 yd²
25.1 yd²
36.7 yd²
57.8 yd²
------------------------------------------------------------------------------------------------------------------------------------------------------------
4.
What is the lateral area of this regular octagonal pyramid?
114.8 cm²
162.4 cm²
229.7 cm²
281.3 cm²
1. We have 12 congruent triangles here
We can find the base of each as
cos 60 = base/14
1/2 = base / 14 multiply both sides by 14
7 = base
We can find the height of each as
sin 60 = a / 14
√3/2 = a / 14 multiply both sides by 14
7√3 = a
So......the area of the hexagon is
12 * (1/2) (base)(height) =
6 ( 7) (7√3) = 294√3 cm^2
2. For the lateral surface area, we have 8 congruent triangles each with the same base as the height because both are opposite 45 degree angles
The base of each triangle = height = 5
So....the lateral surface area =
8 (1/2) (base) (height) =
4 (5)(5) = 100
The area of the base is just side^2 = 10^2 = 100
So.....the surface area = 100 + 100 = 200 ft^2
3. We have 8 congruent 30-60-90 triangles
The base of each = 4.6/ 2 = 2.3
The height of each is opposite the 60° angle = √3 * base = √3 * 2.3
So.....the lateral surface area is
8 (1/2) (base) (height) =
4 (2.3)(√3 * 2.3) ≈ 36.65 yd^2
The base area = side^2 = 4.6^2 = 21.16 yd^2
So....the total area is 36.65 + 21.16 = 57.8 yd^2