10% as a decimal would be .10
Pretty sure that it is 9/7.
Answer:
90 sq inches
Step-by-step 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
Answer:
a. Divide the figure into two rectangles, find the area of each rectangle and add them (See the picture attached).
b. 
c. The total area of the figure is 279 square inches.
Step-by-step explanation:
a. Divide the figure into two rectangles (See the picture attached), then find the area of each rectangle and finally, add the areas calculated in order to get the total area of the given figure,
b. The area of a rectangle can be found using this formula:

Where "l" is lenght and "w" is the width.
Area of Rectangle A
You can identify that:

Then, its area is:

Area of Rectangle B
You can identify that:

Then, its area is:

Total area

c. The total area of the figure is 279 square inches.
4k(3n+2) this is basically just factoring out a common multiple which in this case is a k and a 4