Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
One side of a right-angled triangle is twice the other, and the hypotenuse is 10 cm. The area of the triangle is
(a)$20 \mathrm{cm}^{2}$
(b)$33 \frac{1}{3} \mathrm{cm}^{2}$
(c)$40 \mathrm{cm}^{2}$
(d)$50 \mathrm{cm}^{2}$
Answer
Answer (as printed): A
Explanation
Let the sides be $a \mathrm{cm}$ and $2 a \mathrm{cm}$. Then, $a^{2}+(2 a)^{2}=(10)^{2} \Leftrightarrow 5 a^{2}=100 \Leftrightarrow a^{2}=20$. $$\therefore \quad \text { Area }=\left(\frac{1}{2} \times a \times 2 a\right)=a^{2}=20 \mathrm{cm}^{2} .$$