18. From the top
of a bill, the angles of depression of two consecutive kilometre stones de cast
are found to be 45° and 30° respectively. Find the height of the hill
Answers
Answer:
Let the distance between the nearer kilometre stone and the hill be 'x' km.
So, the distance between the farther kilometre stone and the hill is '1+x' km since both are on the same side of the hill.
In triangle APB,
tan450=xh
⇒1=xh
⇒h=x
In triangle AQB,
tan300=1+xh
⇒31=1+xh
⇒1+x=3h
From equation 1,
1+h=3h⇒1=3h−h
⇒h=3−11
⇒h=1.365km
Answer:
Write Tif it is TRUE and Fif otherwise.
14
1) 51
2) 2666 is an expression
3) -8 < 8
4) 5 > 1 is an expression
5) n + 1 is a sentence
6) -5> 0
7- - < -16
8 - <-16 is not a sentence
9) 5 = 5 is a sentence
10) 14 = 2
11)14 = 2 is a sentence
12) = 20 is not an expression
13) 20 divided by 5 is a sentence.
14)20 divided by 5 is equal to 4 is not a sentence.
15) 0.000066 = 6.6 x 10-5
16)2,560,000 = 2.56 x 105
17)125,000 = 1.25 X 105
18)0.00179 = 1.79 x 10°
19) 27 x 10 = 27,000
20) 60,600,000 = 6,6 x 107