CBSE Class 10 Mathematics (Basic) — Triangles

7. If $\triangle ABC$ and $\triangle DEF$ are similar such that $2AB = DE$ and $BC = 8\text{ cm}$, then EF is equal to : (a) 4 cm (b) 8 cm (c) 12 cm (d) 16 cm

22. (A) In $\triangle ABC$, $DE \parallel BC$. If $AD = x$, $DB = x - 2$, $AE = x + 2$ and $EC = x - 1$, then find the value of x.

22. (B) In the figure given above, $\triangle ABC \sim \triangle XYZ$, then find the values of x and y. ($\triangle ABC$: $AB = 4 \text{ cm}, BC = 6 \text{ cm}, AC = y$; $\triangle XYZ$: $XY = x, YZ = 7.2 \text{ cm}, XZ = 6 \text{ cm}$)

34. (A) State and prove Basic Proportionality Theorem.

34. (B) In the given figure, CM and RN are respectively the medians of △ABC and △PQR. If $\triangle ABC \sim \triangle PQR$, then prove that : (i) $\triangle AMC \sim \triangle PNR$ (ii) $\triangle CMB \sim \triangle RNQ$.