As shown in the figure
Height of helicopter above the ground=30 m
Distance from the base to the point where the person is standing=30 m
height of the person=2 m
Now the person cast the shadow of length x m.
Triangle ABC and triangle EDC are similar.
∵ ∠B= ∠D=90°
∠C is common.
So by AA similarity ΔABC and ΔEDC are similar.
As we know when triangles are similar their sides are proportional.
AB/AD =BC/DC
Let DC=x meter
⇒
⇒5=\frac{30+x}{x}[/tex]
⇒5x=30+x
⇒4x = 30
⇒ x=30/4
⇒ x=7.5 meter
So length of shadow=7.5 meter
2. volume of a sphere of radius r is v (r) =
=4/3π×3
=4π
surface area of a sphere of radius r is 4π
b) Ratio of derivative of volume of sphere to surface area of sphere=
=1 [ incomplete question but you have written few words ]
Step-by-step explanation:
45+90+x=180
135+x=180
x=180-135
x=45
Answer:
See below
Step-by-step explanation:
Here we need to prove that ,

Imagine a right angled triangle with one of its acute angle as
.
- The side opposite to this angle will be perpendicular .
- Also we know that ,


And by Pythagoras theorem ,

Where the symbols have their usual meaning.
Now , taking LHS ,

- Substituting the respective values,





Since LHS = RHS ,
Hence Proved !
I hope this helps.
Answer:
4 + ( -7 X 2 ) = -10
Step-by-step explanation:
Check work:
-7 times 2 is -14.
4 + -14 = -10
Answer: She invested $5000 in an account that pays 6% interest and $10000 in an account that pays 7% interest.
Step-by-step explanation:
Let P be the initial amount she invested in an account that pays 6% interest.
Then, amount invested in other account = 2P
Simple interest = Principal x rate x time
After one year, for the first account,
Interest = P(0.06)(1) = 0.06P
For second account,
Interest = (2P)(0.07)(1)=0.14P
Total interest = 

2P = 2(5000)=10000
Hence, She invested $5000 in an account that pays 6% interest and $10000 in an account that pays 7% interest.