Answer:
a² + b²
Step-by-step explanation:
(a + b)² - 2ab ← expand parenthesis using FOIL
= a² + 2ab + b² - 2ab ← collect like terms
= a² + b²
Answer:
radius 12 units = 452.16 units²
diameter 16.8 units = 221.5584 units²
radius 3.4 units = 36.2984 units²
diameter 10 units = 78.5 units²
Formula for area of circle: 
Answer:
D
Step-by-step explanation:
Write the 2 equations:
5x-2y=18
-5x+3y=-22
You can see that the coefficients of x are opposites, so you can add them(the 2 equations) to eliminate x.
Adding them, you get:
y=-3
So now that you know y, you can substitute the value of y into one of the original equations. Let's substitute it in the first one:
5x+6=18
Solving this, we get:
5x=12
x=12/5
x=12/5, y=-3
1. given
2. measure angle 1 plus measure angle 2 equals 90 degrees
3. B D bisects angle A D C
4. definition of angle bisector
5. definition of congruence
6. measure angle 1 is equal to measure angle 3
7. angle 1 is congruent to angle 3
7. definition of congruence
hope that helps
