Altitudes AD and BE of acute triangle ABC intersect at point H. If angle ABH = 30 and angle DAC = 45, then what is angle HCA in degrees?
In order to solve this problem, let's analyze somethings about it.
First, let's note that right triangles ABC,ABE,ABD,BHD,BEC are all 30-60-90 triangles.
Also, note that right triangles ABE,ADC are 45-45-90 triangles.
In order to solve the problem, let's draw a line to help find HCA for us.
Let's draw the altitude of ABC by connecting c to line segment AB.
This creates a right triangle!
Since we know that
∠BAC=60∘
HCA would have to be 30 degrees because of the right triangle.
So we have
∠HCA=30∘
So 30 degrees is our answer.
Thanks! :)