big triangle angle:
D is a right angle so it would be 90 degrees. angle E is 53 degrees and then thats when you should add 90 and 53 which equals 143 degrees. a whole triangle has 180 degrees in it, so you subtract 180 and 143 which gets you 37.
big triangle length:
if you look at the small triangle you see 5 and 3, you do 20 divided by 5 which equals 4, so you do 4 times 3 which equals 12. so thats the missing length of the big triangle
small triangle angle:
A is a right angle so it would be 90 degrees. angle C is 37 degrees and then thats when you should add 90 and 37 which equals 127 degrees. a whole triangle has 180 degrees in it, so you subtract 180 and 127 which gets you 53.
small triangle length:
if you look at the small triangle you see 20 and 16, you do 20 divided by 5 which equals 4, so you do 16 divided by 4 which equals 4. so thats the missing length of the small triangle
hope i helped
