00:01
Okay, so in b, i have a rectangle, and that is a, b, c, d, and my diagonals are ac, and bd.
00:17
And i know that in a rectangle, that my diagonals are congruent.
00:23
So i know the measure of ac equals the measure of bd.
00:28
So for number 5, 2x plus 15 is going to equal 3x plus 10.
00:38
Subtract 2x from both sides.
00:45
And i have x equal to 5.
00:48
I want to find ac.
00:50
Ac is 2x plus 15.
00:54
2 times 5 plus 15 is 10 plus 15.
00:59
Ac is 25.
01:01
Now in c, i have a rhombus that is f, e, r, m, and m, and f -r -r intersect at l.
01:25
I -f -f -e, or sorry, i -i -f -e, so this angle measures x plus 20, and i -e -e -f -f, measure, x plus 20, and i -e -e -f, measure, x plus 26, i want to find x.
01:48
Well, i know that in a rhombus, the diagonals are perpendicular.
01:53
So i know the measure of ife plus the measure of angle ief has to be 90 degrees.
02:05
So x plus 20 plus x plus 26 is 90.
02:12
That's 2x plus 46 equals.
02:15
Equals 90...