Question

ABCD is a quadrilateral
Work out the length of BC
Give your answer to 1 decimal place

Answer 1

Answer:

8.1

Step-by-step explanation:

Use Pythagoras to find the length of BD- 7.5^2 +5^2=81.25

The square root of 81.25 is 9.01

BD-9.01 cm

Then use the cos rule to find BC.

c=a2+b2﹣2abcosγ=9.012+132﹣2·9.01·13·cos(38°)≈8.09819(square root)

round to 8.1