Question

If the base and height of the right-angle triangle ABC are both reduced by two units. Determine the area of the newly formed triangle.

• A. $3{\text{unit}}^2$
• B. $4{\text{unit}}^2$
• C. $5{\text{unit}}^2$
• D. $6{\text{unit}}^2$

Answer 1

The correct option is A $3{\text{unit}}^2$

Given,
Base of a traingle $=BC=8$
Height of a traingle $=AB=3$
The base and height of right angle triangle ABC is decreased by 2 unit.

Hence,
Base of a new traingle $=BC=8-2=6$
Height of a new traingle $=AB=3-2=1$
For the given triangle $DBE$ right angled at $B$.

As we know,
Area of a new right triangle $=\frac{1}{2}\times \text{base}\times \text{height}$.
$\therefore$ Area $△ABC=\frac{1}{2}\times 6\times 1=3{\text{unit}}^2$
Option (a) is correct.