Question

Using the Incenter P, find the measure of ∠ZPX.

117°

140°

64°

129°

42°

132°

Answer 1

The measure of ∠ZPX is 63°

Explanation:

The given parameters are;

The incenter of the triangle = P

m∠KXP = 31°, m∠PYJ = 27°,
`\overline {ZP}` = 20 feet

Given that the segment
`\overline {XJ}` from the vertex, X, passes through the incenter of the triangle, we have;

The segment
`\overline {XJ}` bisects ∠KXL to form ∠KXP and ∠LXP

Therefore, ∠KXP = ∠LXP = 31°

∠KXL = ∠KXP + ∠LXP = 31° + 31° = 62°

∠KXL = 62°

Similarly;

The segment
`\overline {YL}` bisects ∠KYJ to form ∠PYJ and ∠PYK

Therefore, ∠PYJ = ∠PYK = 27°

∠KYJ = ∠PYJ + ∠PYK = 27° + 27° = 54°

∠KYJ = 54°

In ΔXYZ, we have, ∠LZJ + ∠KYJ + ∠KXL = 180° based on the sum of the interior angles of a triangle postulate

∴ ∠LZJ = 180° - (∠KYJ + ∠KXL) = 180° - (54° + 62°) = 64°

∠LZJ = 64°

The segment
`\overline {ZK}` bisects ∠LZJ to form ∠PZL and ∠PZJ

Therefore, ∠PZL = ∠PZJ

∠LZJ = ∠PZL + ∠PZJ = 2 × ∠PZL = 64°

∠PZL = 64°/2 = 32° = ∠PZJ

In ΔZPX, we have;

∠PZL + ∠LXP + ∠ZPX = 180° based on the sum of the interior angles of a triangle postulate

∠ZPX = 180° - (∠PZL + ∠LXP) = 180° - (32° + 31°) = 63°

∠ZPX = 63°

The measure of ∠ZPX = 63°