Just set it equal to zero and solve using the quadratic equation.
My equation was (1230÷3) ×4 ×this is the multiplication sign
Since the second angle + first angle is 90 degrees, the third angle must be 90 degrees to complete the 180 degrees in a circle.
Hope this helps!
41/19 as a decimal is 2.157895
the nearest hundredth: 2.16