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

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)

7 ft 6 in means 7 1/2, because 6 in is 1/2 of a foot. 7 ft 8 in means 7 2/3 because 8 in is 2/3 of a foot. 23/3 = 7 2/3. 15/2 = 7 1/2.

23/3   *   15/2   = 57 1/2

step-by-step explanation: