Mathematics 10 — Exercise Review · Q3, d

Full question

SQ is a diameter and QSR=72°. Find d=SQR.

Step-by-step solution

1. A radius is perpendicular to the tangent at its point of contact, so the contact angle is 90°.

2. The three angles of a triangle add to 180°. Subtract both known angles.

3. Calculate this operation before combining the remaining terms.

   $$\left(-1\right)\times 90=-90$$

4. Calculate this operation before combining the remaining terms.

   $$\left(-1\right)\times 72=-72$$

5. Substitute the given numbers into the formula.

   $$180-90-72$$

6. Calculate this operation before combining the remaining terms.

   $$180-90-72=18$$

7. The required result is shown below. Unit: °

   $$18$$

Answer

The final answer is shown below.