Question

A triangle has a base of 4 units and a height of 3 units. Mark draws the triangle again but

doubles the height. How does the area of the triangle change?
The area increases by 3 square units.
The area increases by 6 square units.
The area increases by 12 square units.
The area does not change.

Answer 1

Second option: The area increases by 6 square units.

Explanation:

A1 = ½ × 4 × 3 = 6 units²

A2 = ½ × 4 × 2(3) = 12 units²

Increase: 12 - 6 = 6 units²

Answer 2

The area increases by 6 square units.

Explanation:

The original area of triangle

A = 1/2 bh

a = 1/2 (4)*3

6 square units

Now we double the height

A = 1/2 (4) *6

A = 12 square units

The difference is 12-6 = 6 square units