Hey there!
How to calculate Surface area
Step 1: Find the area of the top and the base triangles using the formula, Area of the two base triangles = 2 × (1/2 × base of the triangle × height of the triangle) which simplifies to 'base × height' (bh).
Step 2: Find the product of the length of the prism and the perimeter of the base triangle which will give the lateral surface area = (S1 + S2 + h) × l.
Step 3: Add all the areas together to get the total surface area of a right triangular prism in square units. This means, total surface area of a right triangular prism = (S1 + S2 + h) × l + bh
⇒ SA = (12 + 15 + 9) × 6 + (12)(9)
⇒ SA = (36)(6)+(108)
⇒ SA = 324 square units
Thus, the surface area of the right triangular prism is 324 square units.