# Let ∆ ABC ~ ∆ DEF and their areas be, respectively, 64 cm^{2} and 121 cm^{2}. If EF = 15.4 cm, find BC.

**Solution:**

We know that the ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding sides.

Here it is given that ΔABC ~ ΔDEF

Given, EF = 15.4 cm

Therefore, Area of ΔABC / Area of ΔDEF = (BC)^{2}/(EF)^{2}

64 cm^{2 }/ 121 cm^{2} = (BC)^{2}/(15.4)^{2}

(BC)² = [(15.4)^{2} × 64] / 121

BC = (15.4 × 8) / 11

BC = 11.2 cm

**Video Solution:**

## Let ∆ ABC ~ ∆ DEF and their areas be, respectively, 64 cm² and 121 cm². If EF = 15.4 cm, find BC.

### NCERT Class 10 Maths Solutions - Chapter 6 Exercise 6.4 Question 1:

**Summary:**

Let ∆ ABC ~ ∆ DEF and their areas be, respectively, 64 cm^{2} and 121 cm^{2}. If EF = 15.4 cm, then the value of BC is 11.2 cm.