Answer:
looks like D...............
Answer:
<em>A ≈ 28.5</em>
Step-by-step explanation:
a, b, c
P = a + b + c
Semiperimeter s = 
A = 
~~~~~~~~~~~~~~~
= 4.3 + 2.89 + 6.81 = 14
s = 14 ÷ 2 = 7
= 
= √14.75901 ≈ 3.84
= 8.59 + 7.58 + 6.81 = 22.98
s = 22.98 ÷ 2 = 11.49
= 
= √609.7343148 ≈ 24.6928
= 3.84 + 24.6928 ≈ <em>28.5</em>
To solve this you would use the pythagorean theorem since the brace is making the frame look like two right triangles. The theorem states that for a triangle with a right angle, A^2+B^2=C^2. A and B are the sides of the frame and C is the brace which is like the hypotenuse of the triangle. It doesn't matter which side is A or B so you can put 6 or 8 in place of either in the equation. 6^2+8^2=C^2. If you simplify this it equals 36+64=C^2, which then simplifies to 100=C^2. Then you take the square root of both sides (what number multiplied by itself = the number you are trying to get, in this case, 100). So then you get C=10 because 10x10=100. So the length of the diagonal brace is 10ft.
The answer would be C. both plane A and B because it's on line s which lies on both planes.
