Prove by vector method that an angle in a semi-circle is a right angle.

Prove that an angle inscribed in a semi-circle is a right angle using vector method.

Let ‘O’ be the centre of a circle, PQ is a diameter, then prove that angle PRQ = 90^@ (OR) Prove that angle in a semi-circle is right angle.

Prove by vector method that median to the base of an isoscels triangle is perpendicular to the base.

Prove by vector method, that in a right angled triangle the square of h the hypotenuse is equal to the sum of the square of the other two sides.

Prove by vector method that the diagonals of a rhombus bisect each other at right angles.

Prove by vector method that sin(alpha+beta)=sinalphacosbeta+cosalphasinbeta.

Prove by vector method that the perpendiculars (altitudes) from the vertices to the sides of a triangle are concurrent.

Prove by vector method that cos(A+B)cos AcosB-sinAsinBdot

In triangle ABC , if cosA+sinA-(2)/(cosB+sinB)=0 then prove that triangle is isosceles right angled.

Procedure : (i) Draw three circles of any radius with centre O on chart paper. (ii) From these circles, cut a semi - circle, a minor segment and a major segment (iii) Consider three points on these segment and name them as A,B, and C (iv) Cut the triangles and paste it the graph sheet so that the point A coincides with the origin as shown in the figure. Ovservation : (i) Angle in a Semi - Circle is . . . . . . . . . . angle. (ii) Angle in a major segment is angle. (iii) Angle in minor segment is . . . . . . . angle.