Question

The base of an isosceles triangle is 20 cm. and the altitude is increasing at a rate of 1 cm./min. At what rate is the base angle increasing when the area of the triangle is 100 cm^2?

Answer 1

im confused as to what your asking...can you clarify so I can help you out?

Answer 2

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^ Diagram.
If we were to look at the middle line, h. We can set up a trigonometric function to describe the relation of the increasing altitude and the angle, correct?

Answer 3

We can say:
tan(x)=h/(a/2)=2h/a

but! we know that two of those values are changing with respect to time

dh/dt=1cm/min
So we can get:
tan(dx/dt)=(2dh/dt)/a

Also note that we an figure out the a/2 or a term by recalling the area of a triangle.

Answer 4

I am unable to see your diagram.