In a triangle ABC, side BC = 8.1 cm, side AC = 7 cm, and angle ACB = 30 degrees. What is the area of the triangle?

Initially, one might think to use area = 1/2 x base x height, however drawing the triangle immediately shows that this is not possible here. We then think to use the formula for area using two adjacent sides and the angle inbetween. Looking at our triangle we realise that it is of the correct form. The formula we need to use is = 1/2absinC.In this case, a = 8.1, b = 7, C = 30 degrees, and inputting this into the formula, using that sin30 = 1/2, we get: area = 1/2x8.1x7x1/2 = 14.175.

EB
Answered by Ellie B. Maths tutor

3790 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How do I calculate a percentage increase? For example; there are 15 fish in a fish tank, after a year they have bred and now there are 20 fish in the tank. By what % has the number of fish increased?


The are 10 coloured balls in a bag, 4 red, 3 green, 2 orange and 1 yellow. John picks out balls and replaces them one at a time. What is the probability that the first two he picks are red?


A box contains 7 caramel doughnuts. They have masses of 56 g, 67 g, 45 g, 56 g, 58 g, 49 g and 50 g. Find the median, mean and mode values of these masses. Bonus: What mass of doughnut could be added to the box to make the mean mass = 61 g.


What are surds and how does multiplying them work?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning