Question

PLEASE ANSWER ASAP. I'LL GIVE BRAINLIEST
Prove: If two chords of a circle have a common endpoint and form congruent angles with the radius drawn to that endpoint, then the chords are congruent.

Answer 1

Answer:

.

See the diagram attached below.

Let the chords be AB and AC with common point A.

AD is the diameter. Join B with D and C with D to form two triangles.

We need to prove that AB=AC.

\begin{gathered}In\ \triangle ABD\ and \triangle ACD;\\Given\ that\ \angle BAD=\angle CAD----(condition\ 1)\\since\ AD\ is\ diameter, \angle ABD=\angle ACD = 90^0\\So\ \angle ADB=\angle ADC--------(condition\ 2)\\AD=AD\ (common\ side)-----(condition\ 3)\\ \\So\ the\ triangles\ are\ congruent\ by\ ASA\ rule.\\Hence\ AB=AC.\end{gathered}

In △ABD and△ACD;

Given that ∠BAD=∠CAD−−−−(condition 1)

since AD is diameter,∠ABD=∠ACD=90

0

So ∠ADB=∠ADC−−−−−−−−(condition 2)

AD=AD (common side)−−−−−(condition 3)

So the triangles are congruent by ASA rule.

Hence AB=AC.