What is the area of a triangle with a base of 10 and height of 5?

To find the area of a triangle, the formula used is:

Area = (1/2) × base × height.

In this case, the base of the triangle is 10 units, and the height is 5 units.

Plugging those values into the formula gives:

Area = (1/2) × 10 × 5.

Calculating this, you first perform the multiplication of the base and height:

10 × 5 = 50.

Then, applying the factor of 1/2:

(1/2) × 50 = 25.

Therefore, the area of the triangle is 25 square units. This aligns with the first choice provided. It's an essential concept that emphasizes the relationship between the base and height in determining the area of a triangle, helping reinforce understanding of geometric calculations.