Answer:19. 17 degrees
20. 49 degrees
Step-by-step explanation:
Because of the postulate 50+?=67
So ?=17
And 20.
94+?=143
So
?=49
(Edit)I though you only meant 19 and 20
21. X=8
22. X=12
23.x=8
24.x=7
The total measure of all the angles in a triangle is 180°.
Since there is already a 90° angle, the other 2 angles must also add up to 90°.
The only answer that fits is x = 9.
Check:
9x7 = 63°
3x9 = 27°
Add up = 90°
:)
The formula of a midpoint of a segment AB:

We have:
H(10; 1); K(4; 7)
substitute:

Answer: (7, 4)
Estimation: 500×7=3,500
Product: 503×7=3,521