Question

Expalain Thales theorem

Answer 1

Geometry,
Thales' theorem states that if A, B and C are points on a circle where the line AC is a diameter of the circle, then the angle $\angle ABC$ is a right angle.

Proof:

$x+x+y+y={180}^{\circ }2x+2y={180}^{\circ }2(x+y)={180}^{\circ }$
$\Rightarrow x+y=90degrees$.
Basic Proportionality Theorem (Thales theorem):
If a line is drawn parallel to one side of a triangle intersecting other two sides, then it divides the two sides in the same ratio.