Answer:
D 40 degree and 50 degree
Explanation:
* We can work in units when dealing with tens as 4 + 5 = 9
* As the angle ASD is a Right Angle 4r : 5r = 9r
* 2 angles we see within add up to 90 degree 90 = 9r
ASM + MSO = 90 degree
* 5r = ASM and 4r = MSO = 50 = ASM and 40 = MSO
Therefore ASO - MSO = ASM = 90 - 50 = 40
90 - 50 = 40 and 90 - 5r = 4r
4r = 40 degree and 5r = 50 degree
So just list a few of the above and show that
4r + 5r = 90
9r = 90/9
r = 10
Rounding to zero angles = 40 + 50 = 90 as r = 10
* Answer is D 40 degree and 50 degree