A cube, is made off 6 squarial faces, so all faces on that cube, are squares, the front, back, left, right, top and bottom.
a square has all equal sides, and also all right angles, so all angles in a square are 90°. Let's say the sides are "x" long.
now, if we run a plane on that cube diagonally, check the picture below, the diagonal side at the bottom, by usin the 45-45-90 rule as you see it there, will be x√2.
let's keep in mind that, "x" is opposite side of that angle θ, and then x√2 will be the adjacent side of it.
and we can use those two to get the tangent and then the inverse tangent to get the value, as you see it in the picture.
if you need the angle in radians, run the inverse tangent again, just make sure your calculator is in radians mode.
Answer:
5.) 0.134 kg.
6.) 6.15 km.
7.) 5.9 kg.
Step-by-step explanation:
5.) 0.37 - 0.236 = 0.134
6.) 9.71 - 3.56 = 6.15
7.) 1.7 + 4.2 = 5.9
Answer:
Step-by-step explanation:
A circle is inscribed in an equilateral triangle PQR with centre O. If angle OQR = 30°, what is the perimeter of the triangle?
This is a circle inscribed in an equilateral triangle with side s.
If you are asking for the perimeter of PQR, it is 3s.
If you are asking for the perimeter of OQR, it is (3+23–√3)s
Since OR and SR are the hypotenuses of right triangles with adjacent side equal to ½ s, their length is ½s / cos 30° = (√3) /3.
(3/3)s + ((√3) /3)s + ((√3) /3)s = ((3 + 2√3)/3)s ≈ 2.1547s
Hope it helps
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Answer:
4????
Step-by-step explanation:
Answer:
Step-by-step explanation:
In the diagram below we have
ABCD is a parallelogram. K is the point on diagonal BD, such that
And AK meets BC at E
now in Δ AKD and Δ BKE
∠AKD =∠BKE ( vertically opposite angles are equal)
since BC ║ AD and BD is transversal
∠ADK = ∠KBE ( alternate interior angles are equal )
By angle angle (AA) similarity theorem
Δ ADK and Δ EBK are similar
so we have
( ABCD is parallelogram so AD=BC)
( BC= BE+EC)
( subtracting 1 from both side )
taking reciprocal both side