Answer:
I think it would be 20 hope it helps and good luck
Step-by-step explanation:
12/5 is the answer!
Hope I helped!
Ps: symbolab.com is a great calculator to help solve those type of problems :-)
Both of the other angles are 40° because a triangle has a total angle of 180° and an isosceles triangle means that at least two of the sides have to be the same length (two angles must be the same)
180 - 100= 80
80 ÷ 2 = 40
The equations above are all in the format

, where

= the gradient, or slope.
So, in the first question,

, the gradient would be 4, because 4 is

in this equation (the number before the

).
The gradient of a line perpendicular to this line is equal to the negative reciprocal of the gradient of the line. A better way to explain it is if

= the gradient of the line and <u />

= the gradient of the perpendicular line then:

So in the first question, the gradient of the perpendicular line is

.