SOHCAHTOA (GCSE Maths)
Skill Check
Find the size of the missing angles in the triangles below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the given information
Relative to angle $x$, we have the following lengths:
- The adjacent side is $20\text{ cm}$.
- The hypotenuse is $25\text{ cm}$.
Step 2 ย ยทย Select the trigonometric ratio
Use the cosine ratio, which relates the adjacent side to the hypotenuse:
Step 3 ย ยทย Set up and solve the equation
Substitute the known values and solve for $x$ using the inverse cosine function:
Final Answer
$x = 36.9^\circ$
Find the size of the missing angles in the triangles below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the sides relative to angle $x$
- The adjacent side to angle $x$ is $11\text{ cm}$.
- The hypotenuse of the right-angled triangle is $15\text{ cm}$.
Step 2 ย ยทย Set up the trigonometric equation
Use the cosine ratio, which is $\cos(\theta) = \dfrac{\text{Adjacent}}{\text{Hypotenuse}}$:
Step 3 ย ยทย Solve for $x$ using inverse cosine
Final Answer
$x = 42.8^\circ$
Find the lengths of the sides labelled x below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the given information
- Relative to the $45^\circ$ angle, the adjacent side is $x$ and the hypotenuse is $1.3\text{ m}$.
- Use the cosine trigonometric ratio, which is $\frac{\text{Adjacent}}{\text{Hypotenuse}}$.
Step 2 ย ยทย Set up the equation and solve for $x$
Final Answer
$0.919\text{ m}$
Find the lengths of the sides labelled x below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the given information
Relative to the $60^\circ$ angle, the opposite side is $x$ and the hypotenuse is $4\text{ km}$.
Step 2 ย ยทย Set up the trigonometric equation
Use the sine ratio, which is opposite over hypotenuse:
Step 3 ย ยทย Solve for $x$
Final Answer
$3.46\text{ km}$
Problem Solving
Find the size of the missing angles in the triangles below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the given sides
Relative to angle $x$:
- $\text{Opposite} = 7.4\text{ cm}$
- $\text{Hypotenuse} = 9\text{ cm}$
Step 2 ย ยทย Set up the trigonometric equation
Using the sine ratio $\left(\sin \theta = \dfrac{\text{Opposite}}{\text{Hypotenuse}}\right)$:
Step 3 ย ยทย Calculate angle $x$
Take the inverse sine $\left(\sin^{-1}\right)$ to find $x$:
Final Answer
$x = 55.3^\circ$
Find the size of the missing angles in the triangles below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the given information
Relative to angle $x$, the opposite side is $2.5\text{ cm}$ and the adjacent side is $2.8\text{ cm}$.
Step 2 ย ยทย Choose the trigonometric ratio
Use the tangent ratio, which is opposite over adjacent:
Step 3 ย ยทย Calculate angle $x$
Set up the equation and solve using the inverse tangent function:
Final Answer
$41.8^\circ$
Find the lengths of the sides labelled x below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the knowns and unknowns
- Relative to the $48^\circ$ angle, the adjacent side is $28\text{ cm}$.
- The hypotenuse is $x$.
Step 2 ย ยทย Choose the correct trigonometric ratio
We need the ratio that connects the adjacent side and the hypotenuse, which is cosine:
Step 3 ย ยทย Set up the equation and solve for $x$
Substitute the known values into the ratio and rearrange to find $x$:
Final Answer
$x = 41.8\text{ cm}$
Exam-Style Questions
Find the size of the missing angles in the triangles below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Standardise the units
Convert $1.2\text{ m}$ to $120\text{ cm}$ so all measurements are in the same unit.
Step 2 ย ยทย Identify the sides relative to angle $x$
- The side opposite angle $x$ is $90\text{ cm}$.
- The side adjacent to angle $x$ is $120\text{ cm}$.
Step 3 ย ยทย Use the tangent ratio to find angle $x$
The tangent ratio is $\tan(\theta) = \frac{\text{Opposite}}{\text{Adjacent}}$. Setting up the equation gives:
Final Answer
$36.9^\circ$
Find the lengths of the sides labelled x below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the known values and the correct trigonometric ratio
Relative to the $28^\circ$ angle:
- The adjacent side is $17\text{ cm}$.
- The opposite side is $x$.
- This means we must use the tangent ratio $\left(\tan \theta = \dfrac{\text{Opposite}}{\text{Adjacent}}\right)$.
Step 2 ย ยทย Set up the equation and solve for $x$
Step 3 ย ยทย Calculate the final value
Final Answer
$9.04\text{ cm}$
Find the lengths of the sides labelled x below.

- Take a clear photo of your handwritten work.
- Ensure all calculation steps are legible.
- Upload below for AI Tutor analysis.
Step 1 ย ยทย Identify the sides and choose a ratio
- Relative to the $60^\circ$ angle, the opposite side is $x$.
- The hypotenuse is $50\text{ cm}$.
- This requires the sine trigonometric ratio, which is $\dfrac{\text{Opposite}}{\text{Hypotenuse}}$.
Step 2 ย ยทย Set up the equation and solve for $x$
Substitute the known values into the sine ratio:
Multiply both sides by 50 to isolate $x$:
Step 3 ย ยทย State the final answer
Rounding to 1 decimal place gives:
Final Answer
$43.3\text{ cm}$
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