Answer:
The measure of the fourth angle = 137.1°
Step-by-step explanation:
Let x = the measure of the fourth angle
Sum of all 4 interior angles in a quadrilateral equal 360°
so
x + 23.5° + 99° + 100.4° = 360°
x + 222.9° = 360°
x = 360° - 222.9°
x = 137.1°
9/10. make the bottom numbers the same to add fractions. you can do that by multiplying 7/10 by 10/10.
70/100 + 20/100 = 90/100
90/100 = 9/10
you can also reduce 20/100 to 2/10.
7/10 + 2/10 = 9/10
There are 2/8 in 1/4 and 5/10 in 1/2