The base of a triangle is 21 inches and the height is 12 inches which of these expressions correctly shows how to calculate the area of a triangle
a (21 x 12) divided by 2
b ( 21 + 12) x 2
c (21 + 12) divided by 2
d ( 21 x 12) x 2

A.  (21 × 12) ÷ 2

Step-by-step explanation:

Use the area formula to find the area of the triangle. A = (b × h) ÷ 2

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you

the answer

b. they are parallel and will never intersect.