Answer:
7y8.9 ft²
Step-by-step explanation:
Easy way:
Rotate the triangle so that the 12.1 ft side in on the bottom becomes the base.
Drop a line from the top down perpendicular to the 12.1 ft base. That makes a right triangle.
sin 71 = height/13.8
0.9455 = height/13.8
height = 13.05 ft
Area = bh/2 = (12.1)(13.05)(0.5) = 78.9 ft²
To find x:
Triangles are in total 180 degrees. The two triangles are basically 1 triangle split in half. If the triangle share the same side, has similar angles (shown by the curves on both sides at the top(Angle BAC and CAB), and has similar sides(shown by the hashes made in the lines AC & AB), you can conclude 'x' as a 90 degree angle.
To find y:
The measurment of the angle DCA is 47 degrees. For x, we concluded the answer to be 90 degrees, making the other side of the line 90 degrees as well.Since a triangle is 180 degrees, we can add 47 and 90 to get 137. Taking that answer, we subtract it from the value of 180 degrees to get 43 degrees. So y equals 43.
Mental math is something that can be done i your head.
for example you can do 1+1 in your head and you dont need a calculator or paper to do it so i would be called mental math
Hope this helps
remember if you ever need anything and you dont want to waste points you can just post it on my pfp or message me the question
I think the answer is the third one
Answer:
8640 square inches
Step-by-step explanation:
There are 12 inches in one foot so there would be 12 * 12 = 144 square inches in 1 square foot. Therefore, there are 144 * 60 = 8640 square inches in 60 square feet.