In ∆abc, the median am (m ∈ bc ) is perpendicular to the angle bisector bk (k ∈ ac ). find ab, if bc = 12 in.

The answer is 6 inches

Step-by-step explanation:

Since the angle is isosceles, angle A and angle B have the same measure, 

The sum of the angles of any triangle is 180°.

So 2 times the measure of angle B plus  120° = 180°, then the equation:

Solving for x we get: 

Now we use the law of sine on the triangle BMC like this:

Solving for BC we get : 

We apply the law of sin again on the isosceles triangle ABC like this:

Solving for AB we get:

6 inches

- 70

this is the answer for you hope it

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.