Answer with Step-by-step explanation:
Isosceles triangle :In this triangle two sides are congruent and the angles opposite those sides are congruent.
Right triangle: In this triangle ,one angle is equal to 90 degree.
Suppose a right triangle ABC in which
Angle A=Angle B,Angle C=90 degree
[tex]\angle A+\angle B+\angle C=180^{\circ}[/tex]
Using triangle angles sum property
Substitute the values
[tex]\angle A+\angle A+90=180[/tex]
[tex]2\angle A=180-90=90[/tex]
[tex]\angle A=\frac{90}{2}=45^{\circ}[/tex]
Therefore,
A right triangle in which two equals angle are of 45 degree then the right triangle is an isosceles triangle.
Hence, River's statement is incorrect.
