HARD
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For a regular polygon, let r and R be the radii of the inscribed and the circumscribed circles. A false statement among the following is

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Important Questions on Properties of Triangle

HARD
If p1,p2,p3 are the altitudes of a triangle ABC from the vertices A,B,C respectively, then with the usual notation, 1r12+1r22+1r32+1r2=
MEDIUM
In ΔABC, if a:b:c=4:5:6, then the ratio of the circumradius to its inradius is
EASY
The angles of a triangle are in the ratio 2: 3: 7 and the radius of the circumscribed circle is 10 cm. The length of the smallest side is
HARD

Let ABC be a triangle with BAC=90° and D be the point on the side BC such that ADBC. Let r, r1 and r2 be the inradius of triangles ABC, ABD, and ACD, respectively. If r, r1, and r2 are positive integers and one of them is 5 find the largest possible value of r+r1+r2.

HARD
In a triangle the sum of two sides is x and the product of the same two sides is y. If x2-c2=y, (where c is the third side of the triangle) then the ratio of the inradius to the circumradius of the triangle is
HARD
If in a triangle ABC, AB=5 units, B=cos-135 and radius of circumcircle of ABC is 5 units, then the area (in sq. units) of ΔABC is:
EASY
In a triangle ABC, with usual notation, if a=12, b=16, c=20, then the ratio of the exradii of the triangle opposite to the angles in the order C, B, A is
HARD
If the lengths of the sides of a triangle are 15, 20, 25 units. Find the circumradius of the triangle.
MEDIUM
ln a ABCA=30°+C and R=(3+1)r, where r is the inradius and R is the circumradius, then
MEDIUM
In a triangle 1-r1r21-r1r3=2, then the triangle is
HARD
Three circles of radii 1, 2 and 3 units respectively touch each other externally in the plane. The circumradius of the triangle formed by joining the centres of the circles is
HARD
In ABC, suppose the radius of the circle opposite to an angle A is denoted by r1, similarly r2 angle B, r3 angle C. If 'r' is the radius of inscribed circle then, what is the value of ab-r1r2r3=
HARD
In a triangle ABC, a point D is chosen on BC such that BD:DC=2:5. Let P be a point on the circumcircle ABC such that PDB=BAC. Then PD:PC is :-
EASY
In a ABC, if a-bs-c=b-cs-a then r1, r2 and r3 are
MEDIUM
In a triangle ABC, if a: b: c=4: 5: 6, then 14Rr1+r2+r3=
MEDIUM
If d1, d2, d3 are the diameters of three ex-circles of a ΔABC, then d1d2+d2d3+d3d1=
HARD
Let XY be the diameter of a semicircle with center O. Let A be a variable point on the semicircle and B another point on the semicircle such that AB is parallel to XY. The value of BOY for which the inradius of triangle AOB is maximum, is
HARD
In a XYZ let x, y, z be the lengths of sides opposite to the angles  X, Y, Z respectively and 2s=x+y+z. If s-x4=s-y3=s-z2 and area of incircle of the triangle XYZ is 8π3, then