<span>The simplest method to do this is with the vector dot
product. Let the vector A = <9i + 5j> with magnitude √106 be the base
diagonal, and B = <5j + 3k> be the diagonal vector on the side, with
magnitude √34. Then cos θ = (A dot B) divided by the product of the magnitudes.
A dot B =30, so
cos θ = 30 / √(34 x 106)</span>
<span> = 0.4997 ==></span>
<span> θ = 49.19° is the
answer</span>
Answer:
By comparing the ratios of sides in similar triangles ΔABC and ΔADB,we can say that 
Step-by-step explanation:
Given that ∠ABC=∠ADC, AD=p and DC=q.
Let us take compare Δ ABC and Δ ADB in the attached file , ∠A is common in both triangles
and given ∠ABC=∠ADB=90°
Hence using AA postulate, ΔABC ≈ ΔADB.
Now we will equate respective side ratios in both triangles.
Since we don't know BD , BC let us take first equality and plugin the variables given in respective sides.
Cross multiply
Hence proved.
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Answer: D. (4,3)
The x coordinates of A and B are 9 and -1 in that order. Add them up to get 9+(-1) = 9-1 = 8. Then divide by two to end up with 8/2 = 4. The midpoint has an x coordinate of 4.
Repeat for the y coordinates. Add them up: 8+(-2) = 8-2 = 6. Then divide by two: 6/2 = 3. The midpoint has an y coordinate of 3.
Those two coordinates pair up to get (x,y) = (4,3) which is the midpoint of segment AB.
