Can someone help me understand what I'm supposed to look for in a simple way?

I need help on this too!

There are many examples, you can write anyone:

Vertical angles

∠2 and ∠3

∠1 and ∠4

∠6 and ∠7

∠5 and ∠8

Linear pair

∠2 and ∠4

∠4 and ∠3

∠3 ans ∠1

∠1 and ∠2

∠6 and ∠8

∠8 and ∠7

∠7 and ∠5

∠5 and ∠6

Congruent angles

∠2 and ∠3

∠1 and ∠4

∠6 and ∠7

∠5 and ∠8

the answer is 62.8 cubic units

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis: