Let h = height of triangle
h^2 + 12^2 = 15^2
h^2 + 144 = 225
h^2 = 225 - 144
h^2 = 81
sqrt{h^2} = sqrt{81}
h = 9 cm
For part B, we need to find surface area because it represents the perimeter of this 3-D figure. The formula needed is SA = B + LA.
1. First find the lateral area.
LA = perimeter of triangle • height
LA = ph
p = 15 + 15 + 24
p = 30 + 24
p = 54 cm
LA = (54)(9)
LA = 486 cm^2
2. We now find the base of each triangle. This is found by finding the area of each triangle and multiplying by 2.
A = (1/2)bh
A = (1/2)(24)(9)
A = 108 cm^2
A = 2•108 cm^2
A = 216 cm^2 = our B in the surface area formula.
SA = B + LA
SA = 216 cm^2 + 486 cm^2
SA = 702 cm^2
The amount of cardboard needed is 702 cm^2.
The answer to 8a. is 17, the answer to 8b. is 3.9, the answer to 8c. is 1 / 2, the answer to 8d. is 7 7 / 8, the answer to 9a. is commutative property, the answer to 9b. is multiplicative identity property, the answer to 9c. is associative property, and the answer to 9d. is additive inverse property.
Regarding the whole "explain using mental math" thing, I pretty much just used the fact that 8a. and 8b. both had the same number of decimal places. For 8c., I just made each number have a denominator of 10. And last, for 8d., all of the denominators were already the same, which made it pretty easy. I apologize for this section of my answer being so informal lol, I haven't had to do these kinds of problems in like 5 years <span />
Answer:
c
Step-by-step explanation:
From the graph as x gets larger and becomes positive f(x) approaches 0 so the answer is C.
