(i) Angle AOC would equal 48°, as it is vertically opposite to angle DOB and they are therefore equal.
(ii) Angle DOE would equal 42°. We can see this because angles on a straight line add up to 180°, and 90 + 48 = 138, so we can do 180 - 138 = 42°.
I hope this helps!
Answer:
Step-by-step explanation:
Suppose that the side length is s. Imagine that one side is level. Draw a vertical line through the top vertex perpendicular to the base (level side). Label this vertical line "h." Then h and s are related as follows:
√3 h
sin 60 degrees = ------- = --------
2 s
s√3
and so h = the height of the triangle = -----------
2
The area of this triangle is (1/2)(base)(height), which here is:
(1/2)(s/2)( s√3 /2), or
(s^2)√3
A = ---------------
8
Step-by-step explanation:

Answer:
40° D. is your answer to this question
Answer:
D. 3 and 116
Step-by-step explanation:
d.f.N = k - 1 (numerator degrees of freedom) = 4 - 1 = 3
N = 4 × 30 = 120
d.f.D = N - k (denominator degrees of freedom) = 120 - 4 =116