Answer:
Step-by-step explanation:
Given is the hexagonal pyramid.
We know the radius of the base is same as its side.
<u>Find the base area:</u>
- A = 3√3/2a²
- A = 3√3/2*6² = 54√3
<u>Given the height and radius, find the side of the lateral triangular faces:</u>
Each of 6 triangles have sides 10, 10 and 6 units.
<u>Find the area using heron's formula:</u>
- s = P/2 = (10*2 + 6)/2 = 13
- s - a = s - b = 13 - 10 = 3
- s - c = 13 - 6 = 7
<u>Total surface area:</u>
Correct choice is B
A. When you add to negative numbers, it is always negative. A positive + a positive is positive. In D, the answer is always 0. 1 + -1 is 0. In C, it varies. The bigger number not including the negative sign is the sign the number has. For example, -6 + 5 = -1. 6 is bigger than 5. You subtract the smaller number from the bigger number and that is the answer. You would then tack on the negative sign because it is -6, and 6 is bigger than 5.
Answer: 69
Step-by-step explanation: a triangle adds up to 180 degrees. It is an isosceles triangle (2 sides are the same angle) 180-42=138 then do 138/2=69
