Enlargement by rational scale factorsIB MYP Maths Extended: Mind map

Exam questions on Enlargement by rational scale factors

1. Triangle $ABC$ has vertices $A(2,2)$, $B(6,2)$ and $C(6,8)$. It is enlarged with centre the origin $O$ and scale factor $\frac12$ to give triangle $A'B'C'$.
   Triangle $A''B''C''$ is the image of $ABC$ under an enlargement with centre $O$ and scale factor $-\frac12$. Find the coordinates of $B''$.2 marks
2. Triangle $T$ has vertices $(2,1)$, $(3,1)$ and $(3,3)$. Triangle $T'$ has vertices $(-1,1)$, $(-3,1)$ and $(-3,-3)$. $T'$ is the image of $T$ under a single enlargement.
   A different shape of area 5 cm$^2$ is enlarged by the same enlargement (the same centre and scale factor). Find the area of its image.2 marks
3. A sculptor makes a clay model of a statue. The model is an enlargement of the statue with scale factor $\frac{1}{20}$. The statue is 6 m high, has a surface area of 48 m$^2$ and a volume of 21 m$^3$.
   Find the height of the model in centimetres and the surface area of the model in cm$^2$.3 marks