91Ó°ÊÓ

Trapezoid WXYZ is circumscribed about circle O. \(\angle \mathrm{X}\) and \(\angle \mathrm{Y}\) are right \(\angle \mathrm{s}\) \(\mathrm{XW}=16,\) and \(\mathrm{YZ}=7 .\) Find the perimeter of WXYZ.

A circle is inscribed in a square with vertices \((-8,-3)\) \((-1,-3),(-8,4),\) and \((-1,4)\) a Find the coordinates of the center of the circle. b Find the area of the circle. c Find the radius of a circle circumscribed about the square.

A regular hexagon with a perimeter of 24 is inscribed in a circle. How far from the center is each side?

Find the length of a chord that cuts off an arc measuring 60 in a circle with a radius of 12.

Find the radius of a circle if a \(24-\mathrm{cm}\) chord is \(9 \mathrm{cm}\) from the center.

A 16 -by- 12 rectangle is inscribed in a circle. Find the radius of the circle.

The centers of two circles of radii \(10 \mathrm{cm}\) and \(5 \mathrm{cm}\) are \(13 \mathrm{cm}\) apart. a Find the length of a common external tangent. (Hint: Use the common-tangent procedure.) b Do the circles intersect? (Figure can't copy)

Find the length of each arc described. (The length is a fractional part of the circumference.) a An arc that is \(\frac{5}{8}\) of the circumference of a circle with radius 12 b An arc that has a measure of 270 and is part of a circle with radius 12

Prove: A trapezoid inscribed in a circle is isosceles.

The centers of two circles with radii 3 and 5 are 10 units apart. Find the length of a common internal tangent. (Hint: Use the common-tangent procedure.) (Figure can't copy)