00:01
Okay, so in problem a, i want to find if the measure of bac is 27, so bac, this angle is 27, what's the measure of a, c, b, c, b, b, c, b, and i know that if this angle right here.
00:30
And i know that if this is a rectangle, then i have four right angles.
00:38
So 90 minus 27, that is 63 degrees, which means acb has to be 63 because they are alternate interior angles.
00:50
The measure of dac, we just found that is 63 degrees as well.
00:59
Now in b, we're told that the measure of a, d, e is 74.
01:06
So let me get rid of these.
01:13
A, d, e is 74.
01:17
And i want to find the measure of d -a -e and the measure of b -e -c.
01:27
Okay, so d -a -e is this angle.
01:36
Right here.
01:38
Again, i know that i have four right angles.
01:42
90 minus 74 means this is 16.
01:48
So that means this is 16 and this is 74.
02:00
So i also know that in a rectangle, the diagonals bisect each other.
02:08
So these sides are congruent, which means these angles are congruent.
02:13
So this is also 74, 74.
02:17
So let's see.
02:18
I want d -a -e.
02:22
That is going to be 74 degrees.
02:25
And b -e -c, well, that's 180, minus 16, minus 16, that's 148 degrees.
02:38
Now, in c, i'm told the measure of a -e -b is 140.
02:44
Let me get rid of these.
02:53
Okay, so a, e, b, that is 144.
02:59
And i want to find the measure of cab.
03:04
Okay, so cab is this guy right here.
03:09
180 minus 144 is 36, divide that by 2, 18 degrees.
03:20
Okay, in d, i have the measure.
03:23
Of angle b, c .a as 78 degrees...