posted by Cathy .
A circle has an area equal to 25 pi sq.cm. Its diameter AB coincides with one of the sides of triangle ACB in which the vertex C lies on the circle. If the triangle has an area equal to 11 sq.cm, find its perimeter.
Please include solution. Thanks.
solid mensuration -
The circle radius is 5 cm. That comes from the area.
The triangle ACB is a right triangle with AB as a diameter. The length of AB is 10 cm, since it is a diameter
(AC)^2 + (BC)^2 = (AB)^2 = 100
Area = (1/2)(AB)*(BC) = 11
(AC)*(BC) = 22
(AC)^2 + 484/(AC)^2 = 100
Solve for AC. The short side is about 2.3. Then get BC and the perimenter.
Then get BC