The answer to your question is a=124 because the center triangle is a isosceles triangle
Answer:
A) 147.6 sq m
Step-by-step explanation:
Separate the pyramided out into 4 triangles and add those
3 of them (sides) will be the same

This is one half of the side, multiply by 2 to get the area of the entire side, 40 square m.
The area of all 3 sides together is 40*3 = 120 sq m
For your base, your height will be 6.9 and your base is 4
A = 13.8 sq m
multiply by 2 again for the entire base
A=27.6 sq m
Now add both
120 + 27.6
Answer: m∠E = 55°
Step-by-step explanation: If a triangle has two equal sides, it is called Isosceles. Another characteristics of this type of triangle is that the angles opposite the equal sides are also congruent.
Triangle ΔEFG has two sides with approximately the same length:
≈ 
So, it is an isosceles.
Therefore the opposite angles are m∠E and m∠F.
m∠E = m∠F
m∠E = 55°
Angle at vertex E is 55°.