From figure PA = PC = AC/2 = 14/2 = 7 cm. PA² = AB² + PB² - 2×AB×PB cos ∠PAB {cosine rule} ⇒ 7² = 16² + 129 - 2×16×√129 cos ∠PAB ⇒ cos ∠PAB = (385...

From figure PA = PC = AC/2 = 14/2 = 7 cm. PA² = AB² + PB² - 2×AB×PB cos ∠PAB {cosine rule} ⇒ 7² = 16² + 129 - 2×16×√129 cos ∠PAB ⇒ cos ∠PAB = (385-49)/(32√129) ⇒ cos ∠PAB = 21/(2√129). From ΔPAB PB² = AB² + AP² - 2×AB×AP cos ∠BAC {cosine rule} ⇒ PB² = 16² + 7² - 2×16×7 cos ∠BAC ⇒ PB² = 256 + 49 - 224×11/14 ⇒ PB² = 129. From ΔABCA BC² = AB² + AC² - 2×AB×AC cos ∠BAC {cosine rule} ⇒ 10² = 16² + 14² -