Given:
right triangle
a = 2.9
c = 4.2
Pythagorean Theorem: a² + b² = c²
missing value of b.
b² = c² - a²
b² = (4.2)² - (2.9)²
b² = 17.64 - 8.41
b² = 9.23
b = √9.23
b = 3.03 or 3.0
The value of b is 3.0
J=john
m=mary
j is 2 times as old as mary
j=2 times m
sum is 21
m+j=21
find mary
subsitute
j=2m therefor subsitute 2m for j
m+2m=21
add like terms
3m=21
divide by 3
m=7
mary=7
*HOPE I HELPED!*
126 + x + x = 180
126 + 2x = 180
2x = 54
x = 27
So both the congruent angles measure 27.
Hope this helps :)