One tenth is 0.1. Therefore, the answer has to be 2.x. Since 4 is less than 5, the 2 remains the same. The answer is 2.2.
The area of each triangular face is
.. A = (1/2)*b*h
.. Aside = (1/2)*(6 cm)*(5 cm) = 15 cm^2
The area of the triangular base is
.. Abase = ((√3)/4)*s^2 = (√3)/4*(6 cm)^2 = 9√3 cm^2
The total surface area is the base area plus the area of the three sides.
.. Atotal = Abase + 3*Aside
.. = 9√3 cm^2 +3*15 cm^2
.. = (45 +9√3) cm^2
.. ≈ 60.6 cm^2
Actually, there's an error in the picture. The height of the side should be 4, and the length of the edge should be 5. Making that adjustment, the total area is 51.6 cm^2.
It is hard to tell what is intended. Not all answers are showing, so we can't "reverse-engineer" the problem from the answers.
Answer:
The unknown number is 2/15.
Step-by-step explanation:
4/5+x=14/15
x=14/15-4/5
x=14/15-12/15
x=2/15
