point Q is 20 meters away from the center of the circle.if the diameter of the circle is 10 meters and a line through Q is tangent to the circle at T.find QT

Sagot :

QT^2 = 25 times 15
QT^2 = 375
QT = 19.365
Radius = 1/2 (diameter)
            = 1/2 (10)
            = 5 meters

Point Q is  point outside the circle.  T is a point on the circle and the point of tangency of the circle and QT.

A line tangent to the circle is perpendicular to its radius. Therefore, QT is the base, radius is the leg, and center to Q is the hypotenuse.

Using Pythagorean Theorem:
(QT)² = 20² - 5²
(QT)² = 400 - 25
(QT)² = 375

[tex] \sqrt{(QT) ^{2} } = \sqrt{375} [/tex]

QT = [tex] \sqrt{375} [/tex]

QT = [tex] \sqrt{(25)(15)} [/tex]

QT = [tex]5 \sqrt{15} [/tex] meters