Give the boundaries of the indicated value.
8.64 miles

  8.635 ≤ x < 8.645

Step-by-step explanation:

When a measurement is expressed to a certain precision, it can be because it was rounded to that precision. Rounding up occurs from values that are equal to or greater than 5 in the place to the right of the right-most digit.

That is, the smallest value that will round up to 8.64 is 8.635.

Rounding down occurs from values that are less than 5 in that same number place. Any value less than 8.645 will round down to 8.64.

The boundaries of values that round to 8.64 are ...

  8.635 ≤ x < 8.645

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'.