Which conditional and its converse form a true biconditional?

a) if x> 0, then lxl > 0
b) if x=3, then x2^2=9
c) if x^2 =4, then x=2
d) if x=19, then 2x-3=35

George is 187 cm tall. his son, ralph, is 142 cm tall. who casts the longer shadow. george when the sun is 65° above the horizon, or ralph when the sun is 56° above the horizon? how much longer? (nearest centimeter)

2-3 6. use your equation to find how high tyler will have to climb to scale the peak. (4 points: 2 points for correctly substituting values, 2 points for the correct height)

In parallelogram abcd the ratio of ab to bcis 5: 3. if the perimeter of abcd is 32 find ab