Math  /  Geometry

QuestionUsing Pythagoras' theorem, calculate the length of PR. Give your answer in centimetres (cm) and give any decimal answers to 1 d .p.
Not drawn accurately

Studdy Solution

STEP 1

1. The triangle is a right triangle with PR as one of the legs, RQ as the other leg, and PQ as the hypotenuse.
2. We will use Pythagoras' theorem, which states that in a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.

STEP 2

1. Identify the known values and the unknown value.
2. Apply Pythagoras' theorem to solve for the unknown side.
3. Calculate the length of PR and round to 1 decimal place.

STEP 3

Identify the known values: - RQ = 28 cm - PQ = 35 cm (hypotenuse) - PR = ? (unknown side)

STEP 4

Apply Pythagoras' theorem: PQ2=PR2+RQ2 PQ^2 = PR^2 + RQ^2
Substitute the known values into the equation: 352=PR2+282 35^2 = PR^2 + 28^2

STEP 5

Calculate the squares of the known values: 352=1225 35^2 = 1225 282=784 28^2 = 784
Substitute these values back into the equation: 1225=PR2+784 1225 = PR^2 + 784

STEP 6

Solve for PR2 PR^2 by isolating it on one side of the equation: PR2=1225784 PR^2 = 1225 - 784 PR2=441 PR^2 = 441

STEP 7

Calculate the length of PR by taking the square root of PR2 PR^2 : PR=441 PR = \sqrt{441} PR=21 PR = 21
Since the result is a whole number, no rounding is needed.
The length of PR is:
21 cm \boxed{21 \text{ cm}}

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord