GCSE Secondary Maths Age 13-17 - Geometry & Measures: Area - Triangles and Quadrilaterals - Explained

The video tutorial explains how to calculate the area of a right-angled triangle with sides in the ratio of 3:4:5. It begins by sharing the total perimeter of 72 cm in the given ratio to find the actual side lengths. The lengths are calculated as 18 cm, 24 cm, and 30 cm. Using these measurements, the area is determined by multiplying the base and height and dividing by two, resulting in an area of 216 square centimeters. The tutorial also discusses the allocation of marks for each step in the problem-solving process.

What is the significance of the ratio 3:4:5 in the context of the triangle problem?

• It represents the angles of the triangle.

• It is used to calculate the area directly.

• It is the ratio of the triangle's perimeter.

• It indicates the relative lengths of the sides.

How do you determine the actual lengths of the triangle's sides given the perimeter of 72 cm?

• By dividing the perimeter by 3, 4, and 5.

• By subtracting the ratio from the perimeter.

• By multiplying the perimeter by the ratio.

• By sharing the perimeter in the ratio 3:4:5.

What is the length of the side with the ratio 3 after calculating the actual lengths?

• 18 cm

• 24 cm

• 30 cm

• 36 cm

How is the area of the triangle calculated once the side lengths are known?

• By multiplying the perimeter by the height.

• By using the Pythagorean theorem.

• By adding all the side lengths.

• By multiplying the base and height and dividing by two.

What was the final area of the triangle as calculated in the tutorial?

• 180 square centimeters

• 240 square centimeters

• 200 square centimeters

• 216 square centimeters