In `Delta`PQR, ST is a line such that `(PS)/(SQ) = (PT)/(TR)` and also `anglePST = Delta PEO`.
Prove that `Delta PQR` is an isosceles triangle .

In the given figures (PS)/(SQ)=(PT)/(TR) and /_PST= /_PRQ . Prove that trianglePQR is an isosceles triangles. .

In the given figure, (PS)/(SQ)=(PT)/(TR) and /_PST= /_PRQ . Prove that PQR is an isosceles triangle.

In the given figure, (QT)/(PR) = (QR)/(QS) and angle 1 = angle 2 Prove that Delta PQS ~ Delta TQR .

Prove that the medians of an equilateral triangle are equal.

Prove that the angles opposite to equal sides of an isosceles triangle are equal.

AD, BE and CF are altitudes of triangle ABC. If AD = BE = CF, prove that triangle ABC is an equilateral triangle.

In a right angles triangle, prove that r+2R=s.

If in a triangle r_1=r_2+r_3+r , prove that the triangle is right angled.

In Delta PQR ,right angle is at Q,PQ =3cm and PR =6cm Determine angle QPR and angle PRQ

In triangle ABC, D is the midpoint of BC. DFZAB and DE bot AC, where points F and E lie on AB and AC respectively. If DF = DE, prove that A ABC is an isosceles triangle.