<span>The dot product here is 10(9) + 6(5)=120
so the vectors are not orthogonal
</span><span>u.v = |u| x |v| cos (theta) ; theta is the angle between them
we know from above that u.v = 120
|u| = sqrt[10^2+6^2]=11.66
|v| = sqrt[9^2+5^2]=10.29
so we know:
theta =cos^-1 120/(11.66x10.29)
so theta = 25 degrees</span><span>
</span>
Answer:
18
Explanation:
Square root of 4 is 2. So replace it
(3x2) 3
6 x 3 = 18
9514 1404 393
Answer:
(2) 72°
Step-by-step explanation:
In this geometry, the angle at the tangent is half the measure of the intercepted arc.
∠CBD = (arc BD)/2 = 144°/2
∠CBD = 72°
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<em>Additional comment</em>
Consider a point X anywhere on long arc BD. The inscribed angle at X will have half the measure of short arc BD, so will be 144°/2 = 72°. This is true regardless of the position of X on long arc BD. Now, consider that X might be arbitrarily close to point B. The angle at X is still 72°.
As X approaches B, the chord XB approaches a tangent to the circle at B. Effectively, this tangent geometry is a limiting case of inscribed angle geometry.
