Here is a right-angled triangle - Edexcel - GCSE Maths - Question 9 - 2021 - Paper 2
Question 9
Here is a right-angled triangle.
The shaded shape below is made from two of these triangles.
Work out the perimeter of the shaded shape.
Give your answer correct t... show full transcript
Worked Solution & Example Answer:Here is a right-angled triangle - Edexcel - GCSE Maths - Question 9 - 2021 - Paper 2
Step 1
Find the hypotenuse of the triangle
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Answer
To find the hypotenuse of the right-angled triangle, we can use the Pythagorean theorem:
c2=a2+b2
Here, a=8 mm and b=10 mm. Thus,
c2=82+102=64+100=164
So, the hypotenuse is:
c=extsqrt(164)≈12.81extmm
Step 2
Find the perimeter of the shaded shape
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Answer
The shaded shape consists of 2 triangles. The perimeter of the shaded shape can be found by adding the lengths of all the sides:
The lengths are:
Base: 10 mm
Height on one side: 8 mm
Height on the other side: 8 mm
Hypotenuse from both triangles: 12.81 mm
Thus, the total perimeter is:
P=10+8+12.81=30.81 mm
Rounding to 3 significant figures, the perimeter is: