Question

I need help with these questions.

Answer 1

• See below

Explanation:

Q13

The greater the angle the greater the opposite side

Sides in ascending order:

• AB = 17, AC = 18, BC = 21

Angles in same order

• ∠C, ∠B, ∠A

Q14

As above, sides in ascending order:

• AB = 15, AC = 16, BC = 17

Angles in same order

• ∠C, ∠B, ∠A

Q15

Exterior angle equals to sum of non-adjacent interior angles

• 142° = x + 66°
• x = 142° - 66°
• x = 76°

Q16

Same subject and isosceles triangle:

• x + x = 158°
• 2x = 158°
• x = 79°

Q17

Same subject

• m∠QSR = m∠QPS + m∠PQS
• 2x = x + m∠PQS
• m∠PQS = 2x - x
• m∠PQS = x

ΔPQS has two angles with the measure of x, hence their opposite sides are congruent and the triangle is isosceles