Answer:
45.8
Step-by-step explanation:
We need to find the surface area for this entire figure!
We can see that this is a pyramid here - we must find the area of the 3 triangles and the base triangle at the bottom.
The 3 triangles building up the pyramid are all equal to each other.
To find the area of a triangle, use
Round to the nearest tenth: 45.75 -> 45.8
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
Let the equal sides of the isosceles Δ ABC be x.
Given that the perimeter of Δ ABC = 50m.
Therefore, 2x + AC = 50 --- (1)
It is also given that the perimeter of Δ ABD = 40m.
Therefore, x + BD + AD = 40
BD is the median of the Δ ABC. Therefore, D is the midpoint of AC.
So AD = CD.
Or, AD = AC
Therefore,
Multiply both sides by 2.
2x + 2BD + AC = 80
From (1), 2x + AC = 50.
Therefore, 2BD + 50 = 80
2BD = 80 - 50
2BD = 30
BD = 15m.
