The form he builds is 40 1/2 in. long, 10 in. deep, and 8 in. high. how much cement is needed to fill the form

This question clearly states that it is a 'find the volume' question.

Given dimensions of the object are :

Length of the object = inches or 40.5 inches

Depth of the object = 10 inches

Height of the object is = 8 inches

So, the volume becomes = = 3240 cubic inch

Hence, the amount of cement needed is 3240 cubic inches.

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'.