You can see if the other angles add up to 180 or 360 degrees (depending on shape) then add them to make it the number, for example, if a triangle has a right angle, then the other 2 angles are 45 degrees, knowing that EVERY triangle's angles add up to 180 degrees.
Answer:
d. 54
Step-by-step explanation:
Answer:
1/3
Step-by-step explanation:
5 over 15
divide both by 5 to simplify 1 over 3
Answer:

Since the measurement can't be negative the correct answer for this case would be 
Step-by-step explanation:
Let's assume that the figure attached illustrate the situation.
For this case the we know that the original area given by:

And we know that the initial area is a half of the entire area in red
, so then:

And we know that the area for a rectangular pieces is the length multiplied by the width so we have this:

We multiply both terms using algebra and the distributive property and we got:

And we can rewrite the expression like this:

And we can solve this using the quadratic formula given by:

Where
if we replace we got:

And the two possible solutions are then:

Since the measurement can't be negative the correct answer for this case would be 