WEBVTT
00:00:01.680 --> 00:00:05.080
Determine the perimeter and area of the accompanying figure.
00:00:07.880 --> 00:00:09.180
Let’s start with the perimeter.
00:00:09.530 --> 00:00:13.460
To find the perimeter, we need to add the length of all sides together.
00:00:15.720 --> 00:00:18.320
This trapezoid has four side lengths.
00:00:20.000 --> 00:00:26.260
But one of the side lengths is listed with three separate values that add up to equal it’s one long side.
00:00:28.650 --> 00:00:34.940
So to find the perimeter, we list all the values around the outside of the figure and then add them together.
00:00:37.130 --> 00:00:41.870
When you add all the sides together, it equals 112 millimeters.
00:00:44.270 --> 00:00:52.700
To find the area of a trapezoid, we can use the formula, area equals one-half height times the base one plus base two.
00:00:54.820 --> 00:01:01.790
We’ll call this base one and plug that value into our formula, 20 millimeters.
00:01:03.020 --> 00:01:05.350
We’ll call this value our base two.
00:01:07.420 --> 00:01:10.510
Base two is equal to 52 millimeters.
00:01:10.800 --> 00:01:14.840
You’ll find that if you add 16 plus 20 plus 16.
00:01:17.270 --> 00:01:19.480
And the height of this trapezoid is here.
00:01:19.990 --> 00:01:28.820
The height of any trapezoid is the distance between base one and base two, but it has to be the perpendicular distance.
00:01:29.920 --> 00:01:39.610
This right angle lets us know that it’s a perpendicular distance from base one to base two, and the height of our trapezoid here is 12 millimeters.
00:01:40.650 --> 00:01:46.390
So we plug in 12 for the height and then we solve for area.
00:01:47.930 --> 00:01:51.490
20 plus 52 equals 72.
00:01:52.750 --> 00:01:56.460
One-half times 12 equals six.
00:01:58.290 --> 00:02:03.190
Six times 72 equals 432.
00:02:04.780 --> 00:02:09.400
And because we’re dealing with area, we know that that means millimeters squared.
00:02:12.030 --> 00:02:16.320
For this trapezoid, the perimeter: 112 millimeters.
00:02:16.630 --> 00:02:20.330
And the area: 432 millimeters squared.