Answer:
x=20
3x= 3(20)=60
4x= 4(20)=80
Step-by-step explanation:
The angles CD is 90 degrees because the small square indicates
it. Angles AD are a straight angle, therefore all the other angles within A to D, must equal 180 degree. (straight line/angle=180 degrees).
so AB + 70+ 90= 180 degrees
AB= 180 -70-90
AB=20
x=20
3x= 3(20)=60
4x= 4(20)=80
10% of 65
Of means multiply
=0.1 x 65
=6.5
Or you can use another way which is (part/whole) *(percent/100)
Whole=65
Percent=10
And part(part of 65)=unknown
(X/65)* (10/100)
Cross multiply
x= 6.5
So 10% of 65 is 6.5
Yes he is correcct because 4/8 and 1/2 is the same thing
Answer:
Step-by-step explanation:

Hint: 1 - Cos² A = Sin² A
Answer:
Sin, Cos, Tan and others are used to calculate the ratios of the sides of a right angled triangle by taking a certain angle as the angle of reference.
On the other hand, Sin‐¹, Cos‐¹ and Tan-¹ are used to find the reference angle used to calculate the ratio of sides.
For this question,
we need to find which option should used to calculate the angle the slide makes with the vertical support.
So the option will have to be either A, C or E.
here, the base is 2.81m and hypotenuse is 3.64m.
we know, Cos = base / hypotenuse
So the angle is given by Cos-¹(2.81/3.64)
Option C