math
posted by Amy .
Isosceles Triangle ABC is inscribed in a circle with radius 12cm. Aide AB is a diameter. Determine the perimeter of the triangle, correct to one decimal place.

Point C must be midway between A and B on the circle since the triangle is isosceles. ABC therefore has angles of 45, 90 and 45 degrees. AB has length 12 cm. AC and BC have lengths
6/sin45 = 6*2/sqrt2 = 6 sqrt2
The total perimeter is 12 + 12sqrt2 =
12(1 + sqrt2)= 29.0 cm
Drawing the figure yourself should help explain where I got the above numbers.
Respond to this Question
Similar Questions

geometry
The perimeter of a triangle, its area, and the radius of the circle inscribed in the triangle are related in an interesting way. Prove that the radius of the circle times the perimeter of the triangle equals twice the area of the triangle. 
geometry
The radius of the inscribed circle is equal to twice the area of the triangle divided by the perimeter of the triangle. Prove that this relationship is true for the inscribed circle in any right triangle. 
Math (Geometry)
The perimeter of right triangle ABC is equal to the perimeter of isosceles triangle DEF. The lengths of the legs of the right triangle are 6 and 8. If the length of each side of the isosceles triangle is an integer, what is the greatest … 
Geometry  semicircle inside isosceles triangle
Isosceles triangle ABC has sides of length AB=AC=25 and BC=40 . Find the area of a semicircle inscribed in triangle ABC with diameter along BC . Please help I do not know how to start.... 
GEOMETRY CIRCLE
1.An isosceles triangle with each leg measuring 13 cm is inscribed in a circle . if the altitude to the base is 12 cm find the radius of the circle 2. Circles a and b are tangent at point c. p is on circle a and q is on circle b such … 
GEOMETRY CIRCLES PLEASE
HELP ME PLEASE. 1.An isosceles triangle with each leg measuring 13 cm is inscribed in a circle . if the altitude to the base is 12 cm find the radius of the circle 2. Circles a and b are tangent at point c. p is on circle a and q is … 
Math
The radius of the inscribed circle is 5. If the length of the hypotenuse of the right triangle ABC is 19, what is the perimeter of the triangle? 
math
ABC is an isosceles triangle inscribed in a circle. If AB and AC equal to 2.5cm and BC is 14cm find the radius of the circle 
math
In an isosceles triangle ABC in which AB=AC=6cm is inscribed in a circle of radius 9cm .find the area of triangle 
math
A circle is inscribed in triangle ABC with sides a, b, c. Tangents to the circle parallel to the sides of the triangle are constructed. Each of these tangents cuts off a triangle from ∆ABC. In each of these triangles, a circle …