Double angle (or half angle, depending how you look at it) identities:



So we have



Note that when taking the square root, we should take into account that that could yield two possible solutions, but we know
and
, so it's also the case that
.
Also, the reason we have equality in the last step can be explained like so:

(not unlike the process used to complete the square)
Answer:
Step-by-step explanation:
With reference < H
perpendicular (p) = 12
base (b) = 5
so now
tangent of < H
= p / b
= 12 / 5
hope it helps :)
Look up how to make a histogram and put all the numbers 10 and 12 or whatever
Area of a Trapezoid, A = [(a+b)/2] · h
Where,
a and b are the respective bases of the trapezoid
h is the height of the trapezoid
a = 10
b = 7 + 10 + 10 = 24
h = 9
A = [(a+b)/2] · h
A = [(10 + 24)/2] · 9
A = [(34)/2] * 9
A = 17 * 9
A = 153 Units²
Step 1 : Find the difference [ 891 - 876 = 15 ]
Step 2 : Determine the percentage
Answer: 15% from last year
:)