$-2$

2

$-\frac{1}{2}$

$\frac{1}{2}$

$238\times {10}^3$

$23.8\times {10}^4$

$2.38\times {10}^5$

$0.238\times {10}^6$

1

$\frac{1}{2}$

$a$

$\frac{1}{a}$

$29°28\text{'}$

$29°68\text{'}$

$119°28\text{'}$

$119°68\text{'}$

$60\mathit{\pi c}{m}^2$

$65\mathit{\pi c}{m}^2$

$120\mathit{\pi c}{m}^2$

$130\mathit{\pi c}{m}^2$