You can't because triangles do not have diagonals but an isosceles triangle has 2 equal sides
An isosceles triangle has 3 sides 2 of which are equal in length An isosceles triangle has 3 interior angles 2 of which are the same size
Statement Reason1. triangle ABC is equilateral..............................................given2. AC is congruent to BC;AB is congruent to AC........................................definition of equilateral3. angle A is congruent to angle B;and B is congruent to angle C.............................Isosceles Theorem4. angle A is congruent to angle C..................Transitive Property of Congruence5. triangle ABC is equiangular...............................Definition of equiangular
To prove a trapezoid is isosceles, you need to show that the legs (the non-parallel sides) are congruent. This can be done by demonstrating that the base angles opposite these sides are congruent. You can use the triangle congruence postulates or the properties of parallel lines and transversals to establish the equality of these angles.
What have we got to prove? Whether we have to prove a triangle as an Isoseles triangle or prove a property of an isoseles triangle. Hey, do u go to ALHS, i had that same problem on my test today. Greenehornet15@yahoo.com
Because Corresponding Parts of Congruent Triangles, there are five ways to prove that two triangles are congruent. Show that all sides are congruent. (SSS) Show that two sides and their common angle are congruent. (SAS) Show that two angles and their common side are congruent. (ASA) Show that two angles and one of the non common sides are congruent. (AAS) Show that the hypotenuse and one leg of a right triangle are congruent. (HL)
an isisceles triangle is a triangle with atleast two sides congruent.
Let's draw the isosceles trapezoid ABCD, where AD ≅ BC, and mADC ≅ mBCD. If we draw the diagonals AC and BD of the trapezoid two congruent triangles are formed, ∆ ADC ≅ ∆ BDC (SAS Postulate: If two sides and the angle between them in one triangle are congruent to the corresponding parts in another triangle, then the triangles are congruent). Since these triangles are congruent, AC ≅ BD.
If you can only prove two sides of an apparently equilateral triangle to be congruent then you have to use isosceles.
Suppose the diagonals meet at a point X.AB is parallel to DC and BD intersects themTherefore, angle ABD ( = ABX) = BAC (= BAX)Therefore, in triangle ABX, the angles at the ends of AB are equal => the triangle is isosceles and so AX = BX.AB is parallel to DC and AC intersects themTherefore, angle ACD ( = XCD) = BDC (= XDC)Therefore, in triangle CDX, the angles at the ends of CD are equal => the triangle is isosceles and so CX = DX.Therefore AX + CX = BX + DX or, AC = BD.
Given: AD perpendicular to BC; angle BAD congruent to CAD Prove: ABC is isosceles Plan: Principle a.s.a Proof: 1. angle BAD congruent to angle CAD (given) 2. Since AD is perpendicular to BC, then the angle BDA is congruent to the angle CDA (all right angles are congruent). 3. AD is congruent to AD (reflexive property) 4. triangle BAD congruent to triangle CAD (principle a.s.a) 5. AB is congruent to AC (corresponding parts of congruent triangles are congruent) 6. triangle ABC is isosceles (it has two congruent sides)
The two angle bisectors of a triangle are congruent the those two angles are congruent. The angles are bisected the same meaning that the whole and half angle are the same. For example if they are bisected at the whole angle 50 each, then each half is 25. The bisectors really don't mean anything and all you need is 50 to know it's isosceles. 50 and 50 is 100 and the left over for the last angle is 80 adding to 180. AND overall any 2 congruent angles in a triangle have the same congruent legs making it isosceles.
When you prove a triangle is congruent to another, it can help you prove parts of the triangle congruent by checking the ratio between all sides and angles. Thank you for asking
prove any two adjacent triangles as congruent
An isosceles triangle has 3 sides 2 of which are equal in length An isosceles triangle has 3 interior angles 2 of which are the same size
Let D represent the point on BC where the bisector of A intersects BC. Because AD bisects angle A, angle BAD is congruent to CAD. Because AD is perpendicular to BC, angle ADB is congruent to ADC (both are right angles). The line segment is congruent to itself. By angle-side-angle (ASA), we know that triangle ADB is congruent to triangle ADC. Therefore line segment AB is congruent to AC, so triangle ABC is isosceles.
Statement Reason1. triangle ABC is equilateral..............................................given2. AC is congruent to BC;AB is congruent to AC........................................definition of equilateral3. angle A is congruent to angle B;and B is congruent to angle C.............................Isosceles Theorem4. angle A is congruent to angle C..................Transitive Property of Congruence5. triangle ABC is equiangular...............................Definition of equiangular
If You Prove An Isosceles Triangle To Have Three Equal Sides. You Now Have Disproved It As Being An Isosceles Triangle. So Even If You Could You Would Now Have An Equilateral Triangle. I Just Can`t See A Way This Can Be Done.