HELP In the straightedge and compass construction of the perpendicular line below, how do you know that CD | BE ?

C  angles at the intersection are congruent and supplementary

Step-by-step explanation:

Two right angles are 90° each. So they add up to 180° which makes them supplementary. Supplementary alone is not proof that they are perpendicular because there are many combinations that add to 180.

Congruent means they are identical, or equal in size.

Only two  Right ( 90° ) angles meet those conditions.

341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,