There can be quite a few approaches to do this
A simple yet effective method would be to analyze the slope, you can start by finding the peak location by finding the maximum signal value (granted this is a single peak signal)
then you can detect the edges of the peak by tracing changes to the slope from positive to negative
If the signal may contain more than one peak, you can use the maximal changes in the slope to locate the peak locations as well.
you can use that as a starting point:
x = 1:length(Signal);
y = Signal;
peakIdx = find(y == max(y));
dy = diff(y);
peakStart = find(dy(1:peakIdx-1) < 0, 1, 'last');
peakEnd = find(dy(peakIdx:end) > 0, 1, 'first') + peakIdx;
plot(x(1:peakStart), y(1:peakStart), '-b',...
x(peakStart:peakEnd), y(peakStart:peakEnd), '-g', ...
x(peakEnd:end), y(peakEnd:end), '-r');