well, one line is equal to 180
Starting with the bottom half, there is a right angle so 180-90 is 90
then take the degree that is given to you(47) and subtract it 90-47 is 43
so angle 4 is 43 °
given that,andgle 3 is 90° because its equal to the right triangle on the bottom
2 is equal to 4(43° )
which leaves 1 to be 47°
Hope this helps