Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The base of triangle is 15 cm and height is 12 cm. the height of another triangle of double the area having base 20cm is [IBPS-RRB Office Assistant (Online) Exam, 2015]
(a)22 cm
(b)20 cm
(c)18 cm
(d)10 cm
Answer
Answer (as printed): C
Explanation
Given base of triangle and its height is 15 cm and 12 cm respectively Area of first triangle $=\frac{1}{2} \times$ base × height $$=\frac{1}{2} \times 15 \times 12=90 \text { sq. } \mathrm{cm} .$$ According to given information Let height of triangle be $h$ cm. Area of new triangle $=180 \mathrm{sq} . \mathrm{cm}$. Base = 20 sq. cm. $$\begin{aligned} & \Rightarrow 180=\frac{1}{2} \times 20 \times h \\ & \Rightarrow h=\frac{2 \times 180}{20}=18 \mathrm{cm} . \end{aligned}$$