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.
100 is the common denominator so
70/100 + 20/100 90/100 = 9/10
Answer:
9 pieces
Step-by-step explanation:
28 inches rope cut into 3-inch pieces
There is no matching answer choice, if given numbers are correct then the answer is 9 full pieces
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<u>Note:</u>
- The close answer choice is 8
- 28/8 = 3 1/2 or 3.5
- So if cut into 3.5 inch pieces then it is 8 full pieces
- just in case it was typo 3 instead of 3.5
The second option square root of 2^5
