Aconstruction firm is trying to decide which of two models of a crane to purchase. model a costs $100,000 and requires $8000 per year to maintain. model b has an initial cost of $80,000 and a maintenance cost of $11,000 per year. for how many years must model a be used before it becomes more economical than b?

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'.