The shape of the speed-time graph of a body moving with variable speed depends on the nature of the variation in speed. Here are some common shapes of speed-time graphs for different types of motion:

1. Straight Line: If the body moves with constant speed, the speed-time graph will be a straight line parallel to the time axis. The slope of this line represents the constant speed.

2. Upward Slope: If the body accelerates (increases speed), the speed-time graph will be a line with an upward slope. The steeper the slope, the greater the acceleration.

3. Downward Slope: If the body decelerates (decreases speed), the speed-time graph will be a line with a downward slope. The steeper the slope, the greater the deceleration.

4. Curved Line: If the body's speed changes at a varying rate, the speed-time graph will be a curved line. The shape of the curve depends on the specific pattern of speed variation.

5. Horizontal Line: If the body is at rest (zero speed), the speed-time graph will be a horizontal line at zero speed.

6. Combination of Lines and Curves: In some cases, the speed-time graph may consist of combinations of straight lines and curves, reflecting different phases of motion with constant speed, acceleration, or deceleration.

Remember, the exact shape of the speed-time graph depends on the specific motion of the body and the pattern of speed variation over time.