P is a 21 sided regular polygon. There a...

P is a 21 sided regular polygon. There are exactly `C(21,3)=1330` triangles whose vertices are vertices of P. How many of these triangles are (i) acute? (ii) isosceles? (Isosceles include equilateral.)

Similar Questions

Explore conceptually related problems

A triangle whose on two sides are equal is called an acute triangle (b) a scalene triangle an isosceles triangle (d) an equilateral triangle

A triangle whose two sides are equal is called (a) an acute triangle (b) a scalene triangle (c) an isosceles triangle (d) an equilateral triangle

A triangle whose two sides are equal is known as (a) acute triangle (b) an isosceles triangle (c) a scalene triangle (d) a right triangle

A triangle whose two sides are equal is known as acute triangle (b) an isosceles triangle a scalene triangle (d) a right triangle

A triangle whose all sides are equal is called an equilateral triangle (b) an acute triangle a right triangle (d) an isosceles triangle

Find the area of triangle whose vertices are P(3/2,1),Q(4,2), R(4,-1/2)

The base vertices of an isosceles triangle PQR are Q (1,3) and R(-2, 7). The vertex P can be-

The base vertices of an isosceles triangle P Q R are Q=(1,3) and R=(-2,7) . The vertex P can be

A triangle whose all sides are equal is called (a) an equilateral triangle (b) an acute triangle (c) a right triangle (d) an isosceles triangle

A regular polygon has 20 sides.How many triangles can be drawn by using the vertices, but not using the sides?