MS Paint will apply the text to the image. The only way out is to re-do everything as it doesn’t record steps if you have left the text area. Since there is no concept of layering in MS Paint ...

text{Area of a triangle} = \frac{1}{2} ab \sin{C}\) To calculate the area of any triangle the lengths of two sides and the angle in between are required. Rearrange the equation to make \(\sin{C}\) ...

Don't forget for the total surface area, you will need to add the area of the circular base: \(\text{Area of a circle} ~=~ \pi \times {r}^{2}\) 3. \(\text{Curved surface area of a cone} ...