Question

1) If sin = 1, then cot =?
2) How many common tangents can be drawn to two circles which touch each

other externally?

3). From the information given in the figure, find the measure of ∠AEC.
4)The ratio of corresponding sides of similar triangles is 5 : 7, then what is the

ratio of their areas ?
​

Answer 1

Let x

1

,x

2

,x

3

,x

4

be four observations.

According to question

4

x

1

+x

2

+x

3

+x

4

=20

⇒x

1

+x

2

+x

3

+x

4

=80

After adding ’c’ to each observation the new A.M.