State the number of significant figures in the following measurements :
(a) `2.80xx10^(8)`
(b) `8.034`
(c ) `0.0009`.

Explanation

To determine the number of significant figures in the given measurements, we will analyze each measurement step by step.

### Step 1: Analyze the first measurement `2.80 x 10^8`
- The number `2.80` has three digits: `2`, `8`, and `0`.
- The `0` in `2.80` is significant because it is to the right of a decimal point and follows a non-zero digit.
- The scientific notation part `x 10^8` does not affect the count of significant figures.

**Total significant figures in `2.80 x 10^8`: 3**
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