 Hello and welcome to the session. I am Asha and I am going to help you with the following problem that says BE and CF are two equal altitudes of triangle ABC using RHS congruence rule proves that the triangle ABC is isosceles. So let us see the ABC triangle in which the two altitudes BE and CF are equal. So here we are given a triangle ABC such that the altitudes BE is equal to CF. And we have to prove that triangle ABC isosceles that is any of its two sides are equal. We should show that AB is equal to AC. Let us now start with the proof. Now let us see in triangle BCF and CBE. Now in these two triangles BC is equal to CB this is the side which is common to both the triangles. And let us name these two angles as angle 1 and angle 2. Now angle 1 is equal to angle 2 is equal to 90 degrees since BE is perpendicular on AC and CF is perpendicular on AB. Since BE and CF are the two altitudes also we are given that BE is equal to CF. Hence by RHS congruence rule we have triangle BCF congruent to triangle CBE which further implies that angle B is equal to angle C by CBCT. That is corresponding parts of congruent triangles are equal. Now in triangle ABC here angle B is equal to angle C. So this implies the side opposite to angle B which is AC is equal to the side opposite to angle C which is AB since both angles are equal. Hence this implies triangle ABC is an isosceles triangle. So this is what we have to prove. So this completes it. Hope you have understood it. Take care and have a good day.