If the sides of `DeltaABC` in the ratio 4 : 5 : 6, prove that one angle is twice that of the other.

In DeltaABC , The sines of the angles of a triangle are in the ratio of 4 : 5 : 6, prove that the cosines of the angles are 12 : 9 : 2.

If P, Q, R divide the sides BC, CA and AB of DeltaABC in the same ratio, prove that the centroid of the triangles ABC and PQR coincide.

If one diagonal of a trapezium divides the other diagonal in the ratio 1:2, prove that one of the parallel lines is double the other.

If the sides of a triangle are 3, 5, and 6, prove that the triangle is obtuse - angled triangle and find the obtuse angle.

If the angles of a triangle are in the ratio 4:1:1, then the ratio of the longest side to the perimeter is

Which of following indicates that Delta ABC is a right triangle? (I) The angle of Delta ABC are in the ratio 1 : 2 : 3. (II) One of the angles of DeltaABC equals the sum of the other two angles. (III) DeltaABC is similar to the right triangle DletaDEF .

The sides of a triangle are in a ratio of 4:5:6. the smallest angle is

The angle of a triangle are in the ratio 1 : 2 : 7, prove that the ratio of the greatest side to the least side is (sqrt(5)+1):(sqrt(5)-1) .

The angles of a triangle are in the ratio 3 : 5 : 10, the ratio of the smallest side to the greatest side is

In a DeltaABC , if a = 4, b = 5 , c = 6 then angle C is equal to