SAT MAth Practice questions – all topics
- Geometry and Trigonometry Weightage: 15% Questions: 5-7
- Area and volume
- Lines, angles, and triangles
- Right triangles and trigonometry
- Circles
SAT MAth and English – full syllabus practice tests
Question medium
For the triangle shown, which equation is NOT true?
A. \(\sin x=\frac{42}{59}\)
B. \(\sin \left(90^{\circ}-x\right)=\frac{42}{59}\)
C. \(\cos \left(90^{\circ}-x\right)=\frac{42}{59}\)
D. \(\sin \left(90^{\circ}-x\right)-\cos x=0\)
▶️Answer/Explanation
Ans:B
Given \(\sin x =\frac{\text{Perpendicular}}{\text{Hypot.}}= \frac{42}{59}\), we know that in a right triangle, the sine of an angle is the ratio of the length of the side opposite the angle to the length of the hypotenuse.
\(\sin \left(90^{\circ}-x\right)=cos x\)
From triangle , \(\cos x =\frac{\text{base}}{\text{Hypot.}}\)
\(\cos x =\frac{\text{41.4}}{\text{59}}\) So option- B is wrong
Question medium
An isosceles right triangle has a hypotenuse of length 4 inches. What is the perimeter, in inches, of this triangle?
A. \(2 \sqrt{2}\)
B. \(4 \sqrt{2}\)
C. \(4+4 \sqrt{2}\)
D. \(4+8 \sqrt{2}\)
▶️Answer/Explanation
Ans:C
An isosceles right triangle has two equal sides, each of which is the same length. In this case, the hypotenuse is given as 4 inches.
By the Pythagorean theorem, if \(a\) and \(b\) are the lengths of the two legs of the right triangle, and \(c\) is the length of the hypotenuse, then \(a^2 + b^2 = c^2\).
Since it’s an isosceles right triangle, the legs are equal. Let’s call the length of each leg \(x\).
So, \(x^2 + x^2 = 4^2\).
Solving for \(x\):
\[2x^2 = 16\]
\[x^2 = 8\]
\[x = \sqrt{8}\]
\[x = 2\sqrt{2}\]
The perimeter of the triangle is the sum of all three sides:
\[P = 2x + 4\]
Substituting the value of \(x\):
\[P = 2(2\sqrt{2}) + 4\]
\[P = 4\sqrt{2} + 4\]
So, the correct answer is option C: \(4 + 4\sqrt{2}\).
Question medium
Rectangle X has a length of 12 centimeters (cm) and a width of 2.5 cm. Right triangle Y has a base of 10 cm. The area of rectangle X is three times the area of right triangle Y. What is the height, in cm, of right triangle Y?
A. 1
B. 2
C. 3
D. 6
▶️Answer/Explanation
Ans: B
The area of a rectangle is given by the formula \( \text{Area} = \text{length} \times \text{width} \). Similarly, the area of a right triangle is given by \( \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} \).
Given that the area of rectangle \( X \) is three times the area of right triangle \( Y \), we can set up the equation:
\[ 12 \times 2.5 = 3 \times \frac{1}{2} \times 10 \times \text{height of triangle } Y \]
\[ 30 = 15 \times \text{height of triangle } Y \]
\[ \text{height of triangle } Y = \frac{30}{15} = 2 \]
So, the height of right triangle \( Y \) is \( 2 \) centimeters. Therefore, the correct answer is option B, \( 2 \).
Question medium
Which of the following additional pieces of information provides enough information to prove whether triangle DEF is a right triangle?
I. The measure of angle D
II. The length of segment DF
A. I only
B. II only
C. Either I or II
D. Neither I nor II
▶️Answer/Explanation
Ans: C
To determine if a triangle is a right triangle, we need to either know the measure of one of its angles being 90 degrees, or use the Pythagorean theorem to check if the sum of the squares of the lengths of two sides equals the square of the length of the third side.
- The diagram shows a triangle DEF with side lengths DE = 3 units and EF = 5 units.
I. The measure of angle D:
If the measure of angle D is 90 degrees, then triangle DEF is definitely a right triangle.
If the measure of angle D is not 90 degrees, then we can determine that triangle DEF is not a right triangle.
II. The length of segment DF:
If we know the length of segment DF, we can use the Pythagorean theorem to check if $\rm{DF^2 = DE^2 + EF^2}$. If this equation holds true, then the triangle is a right triangle.
Therefore, the correct answer should be C. Either I or II
Questions Medium
Triangle ABC is similar to triangle DEF, where angle A corresponds to angle D. What is the value of cos F ?
▶️Answer/Explanation
Ans: 4/5, .8
Since the triangles are similar, their corresponding angles are equal. Therefore, we have: Angle A \(=\) Angle \(D\)
From the given figure, we can observe that angle \(\mathrm{F}\) is the complement of angle \(\mathrm{A}\) (or angle D).
Angle \(\mathrm{F}=90^{\circ}\) – Angle A
To find the value of \(\cos \mathrm{F}\), we need to know the value of angle \(\mathrm{F}\) in degrees.
Using the trigonometric ratio for cosine:
\[
\cos \mathrm{F}=\cos \left(90^{\circ}-\mathrm{A}\right)=\sin \mathrm{A}
\]
\( \begin{aligned} \operatorname{Sin A} & =\frac{\text { Perpend. }}{\text { Hypot. }} \\ & \operatorname{Sin A}=\frac{24}{30} \\ & \operatorname{Sin A}=\frac{4}{5}\end{aligned} \)