It is given that line segment BC is congruent to line segment EC and that line segment AC is congruent to DC. Because of the vertical angles theorem, angle BCA is equal to angle DCE. Therefore, triangles CBA AND DEC are congruent by SAS. Using CPCTC, BA is equal to ED.
The expansion of a perfect square is

In words, the square of a sum of two terms is the sum of the squares of the two terms (
and
), plus twice the product of the two terms (
)
So, when determining if you have a perfect square trinomial, you should have two perfect squares. Note that they don't have to be the first and third term, since you can rearrange terms as you prefer.
Answer:
Percent means the number out of 100
use the formula ( Value you got / Original value) X 100
for percentage increase or decrease = (Change in value / original value) X 100
Step-by-step explanation:
Let be x the number of rows
there are 1200 seats, and each row has 20seats
so 20x=1200, so x= 60, there are 60 rows in the theater