# Inscribed Right Triangle

How to solve inscribed right triangle problems: property, proof, examples, and their solutions.

## Property

If the side of an inscribed triangle

passes through the center of the circle,

then that triangle is a right triangle.

## Proof

m[blue arc] = 180

The red angle is the inscribed angle

that intercepts the blue arc.

So m∠(red) = (1/2)⋅180 = 90.

So the given triangle is a right triangle.

## Example 1

The side of the given triangle

passes through the center of the circle.

(blue point)

So the given triangle is a right triangle.

The measures of the triangle's interior angles are

30, *x*, and 90.

So it's a 30-60-90 triangle.

So *x* = 60.

## Example 2

The side of the given triangle

passes through the center of the circle.

(blue point)

So the given triangle is a right triangle.

See the given right triangle.

The brown hypotenuse is, 13 + 13, 26.

And the leg is 10.

So this right triangle is similar to (5, 12, 13) right triangle.

Draw a (5, 12, 13) right triangle next to the given triangle.

The given triangle is × 2 bigger.

So *x* = 2⋅12.