Answer:
90 sq inches
Explanation:
The lateral area is the side area of the pyramid. In this case, there are 3 sides because the base is a triangle. Since the base is an equilateral triangle, all sides are of equal dimensions. So, the sides of the pyramid are also all of the same size, area.
We then just have to figure out the area of one of the side triangles, then multiply it by 3 to get the total lateral area of that pyramid.
We know how to calculate the area of a triangle: A = (b * h)/2
In this case, b = 5 in, h = 12 in. So,
TA = (5 * 12)/2 = 60 / 2 = 30
Each side triangle has an area of 30 sq inches.
LA = 3 * TA (since there are 3 sides)
LA = 3 * 30 = 90 sq inches