00:01
In this problem, we're this triangle with these sides, and we're asking that we're going to find out of the angle gamma.
00:11
We're going to use this formula.
00:14
Now, we know that the 90 will be the side a, the 70, the side b, and the 40 the side c.
00:24
So, we're to substitute these values in the formula.
00:28
So we're going to have 40 80 to quadrado is equal to 90 squared plus 70 to quadrado minus 2 for 90 for 70 by cos gamma now, we're going to simplify this 40 to quadrado is 1 ,600 when you put these 2 in the calculator 1st000 minus the product of these 3 ,000 the multiplication of these three numbers will be 12 ,600 cos gamma.
01:15
Now we're going to resolve for the cos gamma.
01:17
First, we're going to rest 13 ,000 of the two sides and the resta here, to be negative 11 ,000 400...