PMN and PQR are two secants of the circle MQTRN and PT is a tangent. If PM = 5cm, PN = 12cm and PQ = 4.8cm, calculate the respective lengths of PR and PT in...
PMN and PQR are two secants of the circle MQTRN and PT is a tangent. If PM = 5cm, PN = 12cm and PQ = 4.8cm, calculate the respective lengths of PR and PT in centimeters
Answer Details
In this problem, we are given a circle MQTRN and two secants PMN and PQR intersecting at point T and a tangent PT.
First, we can use the theorem that states that the product of the lengths of the two segments of each secant is equal. So we have:
PM * PN = PT * PR
Substituting the given values, we get:
5cm * 12cm = PT * PR
60cm² = PT * PR
Next, we need to find the respective lengths of PR and PT. To do this, we can use the Pythagorean theorem, which states that in a right triangle, the square of the hypotenuse (the longest side) is equal to the sum of the squares of the other two sides. In triangle PRT, PT is the hypotenuse, so we have:
PT² = PR² + RT²
We can also use the fact that RT is perpendicular to PT, which means that triangle PRT is a right triangle.
To find RT, we can use the theorem that states that the product of the segments of a secant and its external part is equal. So we have:
PT * TP = QT * TR
Substituting the given values, we get:
PT * PT = 4.8cm * TR
PT² = 4.8cm * TR
TR = PT² / 4.8cm
Now we can substitute RT in the Pythagorean theorem and simplify:
PT² = PR² + (PT² / 4.8cm)²
PT⁴ / (4.8cm)² = PR²
PR = sqrt(PT⁴ / (4.8cm)²) = PT² / 4.8cm
Finally, we can substitute the value of PR in the first equation we obtained and solve for PT:
60cm² = PT * (PT² / 4.8cm)
PT³ = 288cm³
PT = cube root of 288cm³ ≈ 6.67cm
Now we can substitute the value of PT in the equation we obtained for PR:
PR = PT² / 4.8cm ≈ 7.7cm
Therefore, the respective lengths of PR and PT are approximately 7.7cm and 6.67cm, respectively. So the answer is 7.7, 12.5.