What is the value of x to the nearest tenth?

First make a triangle by connecting the center point of the circle to one of the end points of the chord.

This will make a right triangle. The new formed line is the radius of the circle and will be the hypotenuse of the right triangle too.

Since one of the legs of the right triangle is half the chord, divide the chord in to two.

9.6 / 2 = 4.8

Now we can calculate for the hypotenuse.

Pythagorean theorem states that  a²+b² = c²

So

√2.4² + 4.8² = c

√5.76 + 23.04 = c

√28.8 = c

5.4 = c

C is the hypotenuse and the hypotenuse is known as the radius of the circle.

So the radius is 5.4

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.