Progression (Sequence and Series)Hard

Question

In a triangle the lengths of the two larger sides are 10 and 9, respectively. If the angles are in AP, then the length of the third side can be

Options

A.
B.3√3
C.5
D.None of these

Solution

      
Since, angles of a triangle are in AP.
⇒     α + (α - δ) + (α + δ) = 180o
⇒         α = 60o
Using cosine law in ᐃABC,
cos 60o =
⇒      
⇒       x2 = 91
⇒       x =

Create a free account to view solution

View Solution Free
Topic: Progression (Sequence and Series)·Practice all Progression (Sequence and Series) questions

More Progression (Sequence and Series) Questions

Which of the following is not a measure of dispersion?...A boy goes to school from his home at a speed of x km/hr. and comes back at a speed of y km/ hr. then the average speed ...The number of terms in the sequence 1,3, 6,10, 15,21,...., 5050 is-...The positive integer n , for which the solutions of the equation$${x(x + 2) + (x + 2)(x + 4) + \ldots. + (x + 2n - 2)(x ...The geometric mean of the numbers 4, 8, 16 is-...