By how many times will the area of a triangle increase, if the base and the height are increased by 2 times?
Let h be the height of the triangle and b be the base of the triangle.
The area of the triangle A=$\dfrac{1}{2}$bh
The length of the base and the length of the height are increased by 2 times.
The new base is $2 \times b $ and the new height is $ 2 \times h.$
The new area of the triangle = $\dfrac{1}{2} \times (2 \times b) \times (2 \times h)$
= 4 $\left(\dfrac{1}{2}bh\right)$
= 4 × original area of the triangle
The area of the triangle increases by 4 times.