To find the area of a rhombus, multiply the lengths of the two diagonals and divide by 2 (same as multiplying by 1/2): The sides and angles of a rhombus: The sides of a rhombus are all congruent (the same length.) Opposite angles of a rhombus are congruent (the same size and measure.)
A square has two perpendicular bisectors but a square is not a rhombus (because a rhombus does not have all four angles = 90. Oh, but wait, a rhombus is a square in the same way a rectangle is a square but not the other way around.
Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
= 
(2sin20°cos20°)cos40°cos80°
= 
(2sin40°cos40°)cos80°
= (sin80°cos80° )
= 
(2sin80°cos80° )
= . sin160°
= . sin(180 - 20)°
= . sin20°
= 
= right side , thus proven
F = 18 ft.
The law of cosines states
c² = a² + b² - 2ab cos C
Using our information, we have
c² = 23² + 16² - 2(23)(16)cos 52
c² = 529 + 256 - 736cos 52
c² = 785 - 736cos 52
c² = 331.8732
Taking the square root of both sides, we have
c = √331.8732 = 18.22 ≈ 18
Having the angle in radians and the diameter of the circle we can easily calculate the length using the following expression
Length = angle(radians)*diameter/2
With this expression we can easily deduce the perimeter of a circle (length of the full arc)
Length = Perimeter = 2*pi*r
There is only one operation involved in this process
