In a right-angled triangle ABC, the height CP is drawn so that the length of the segment AP is 4 cm longer than the length
In a right-angled triangle ABC, the height CP is drawn so that the length of the segment AP is 4 cm longer than the length of the segment CP, and BP = 9 cm. Find the hypotenuse of triangle ABC.
The height СР divides the triangle ABC into two similar in acute angle triangle BCP and ACP.
Then CP / AP = BP / CP.
Let the length of the height CP = X cm, then, by condition, AP = X + 4 cm.
X / (X + 4) = 9 / X.
X ^ 2 = 9 * X + 36.
X ^ 2 – 9 * X – 36 = 0.
Let’s solve the quadratic equation.
D = b^2 – 4 * a * c = (-9) ^ 2 – 4 * 1 * (-36) = 81 + 144 = 225.
X1 = (9 – √225) / 2 * 1 = (9 – 15) / 2 = -6 / 2 = -3. (Doesn’t fit.)
X2 = (9 + √225) / 2 * 1 = (9 + 15) / 2 = 24/2 = 12.
CP = 12 cm, then AP = X + 4 = 12 + 4 = 16 cm.
AB = AP + BP = 16 + 9 = 25 cm.
Answer: The length of the hypotenuse is 25 cm.