(100) What’s the distance of all the sides combined, add the method.

Answer:
As AE and BD intersect:
As AB is parallel to ED:
Therefore, we can use SSS Similarity Theorem to find the lengths of the sides:
[tex]\sf \dfrac{AC}{EC}=\dfrac{BC}{DC}=\dfrac{AB}{ED}[/tex]
[tex]\implies \sf \dfrac{400}{1000}=\dfrac{300}{ED}[/tex]
[tex]\implies \sf 400 \cdot ED=300 \cdot 1000[/tex]
[tex]\implies \sf ED=\dfrac{300000}{400}=750[/tex]
**The length of BC and CD cannot be determined without knowing an angle**
Therefore, the remainder of the calculations are based on the assumption that ∠BAC and ∠DEC are 90°
If ∠BAC = 90° then BC can be calculated using Pythagoras' Theorem
⇒ AB² + AC² = BC²
⇒ 300² + 400² = BC²
⇒ BC² = 250000
⇒ BC = 500
Using the side ratios stated previously:
[tex]\sf \dfrac{AC}{EC}=\dfrac{BC}{DC}=\dfrac{AB}{ED}[/tex]
[tex]\implies \sf \dfrac{400}{1000}=\dfrac{500}{DC}[/tex]
[tex]\implies \sf 400 \cdot DC=500 \cdot 1000[/tex]
[tex]\implies \sf DC=\dfrac{500000}{400}=1250[/tex]
Therefore, the distance of each side is:
Assuming the sides are the solid lines marked with arrows only:
⇒ Total distance = AB + BC + DC + ED
= 300 + 500 + 1250 + 750
= 2800 m